This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.
 | Rotalia beccariformis White, 1928 = Gavelinella beccariiformis | ||
 elegans/Fornasini 1906 pl. 1 fig. 10.jpg) |  elegans/Parker, Jones & Brady 1871 pl. 12 fig. 142.jpg) | Rotalia Turbinulina elegans d’Orbigny, 1826 = Hoeglundina elegans | |
 | Rotalia aequilateralis Plummer, 1927 = Gyroidinoides aequilateralis | ||
 | Rotalia ambigua Franzenau, 1888 = Planulina ambigua | ||
 | Rotalia ammophila Gümbel, 1868 = Hanzawaia ammophila | ||
 | Rotalia beccariiformis White, 1928 = Stensioeina beccariiformis | ||
 | Rotalia capitata Gümbel, 1868 = Anomalinoides capitatus | ||
 | Rotalia convexa Leroy 1953 = Angulogavelinella avnimelechi | ||
 | Rotalia ecuadorensis Galloway & Morrey 1929 | ||
 | Rotalia eocaena Gümbel, 1868 = Cibicidoides eocaenus | ||
 | Rotalia flosculiformis Schwager, 1866 = Hoeglundina elegans | ||
 | Rotalia parvula ten Dam, 1944 = Spiroplectinella subhaeringensis | ||
 | Rotalia propinqua Reuss, 1856 = Cibicidoides eocaenus | ||
 | Rotalia schloenbachi Reuss, 1863 = Osangularia schloenbachi | ||
 | Rotalia soldanii var. subangulata Plummer 1926 = Gyroidinoides subangulata | ||
 | Rotalia truncana Gumbel, 1868 = Cibicidoides truncanus |
Current identification:
Original Description
Ce genre est encore un de ceux qui appartiennent à la singulière famille des mollusques céphalopodes à coquille multiloculaire, et conséquement il a des rapports avec les nautiles, les ammonites, les discorbites, les nummulites, etc. Ainsi l’on peut présumer que les coquilles qui s’y rapportent étoient enchâssées dans l’extrémité postérieure de l’animal dont elles proviennent.
Les Rotalies, qu’il faut nommer rotalites, parce qu’on n’en connoit que de fossiles, sont de très-petites coquilles en spirale orbiculaire, convexes ou un peu coniques en dessus, dont les tours sont contigus et distincts, et dont la base, qui est la partie la plus large de la coquille, est aplatie, tuberculeuse ou granuleuse, et garnie de rayons onduleux. Ces rayons sont les interstices des saillies que font les loges du dernier tour de la spirale.
L’ouverture de la coquille est celle de sa dernière loge; elle est marginale, trigone, et semble renversée ou dirigée vers la base. Les cloisons transversales qui separent les loges sont dirigées comme des rayons vers le centre ou l’axe de la coquille; en sorte que les loges sont légèrement coniques.
[Google Translated from Latin]: Shell univalve, spiral, convexo-conical, radiate beneath. Spira multilocular. Marginal aperture, trigonous, resupinated.
[Google Translated from French]: This genus is still one of those which belong to the singular family of cephalopod molluscs with multilocular shells, and consequently it has relations with nautiluses, ammonites, discorbits, nummulites, etc. Thus one can presume that the shells which relate to it were embedded in the posterior end of the animal from which they came.
Rotalies, which must be called rotalites, because they are only known from fossils, are very small orbicular spiral shells, convex or slightly conical above, whose turns are contiguous and distinct, and whose base, which is the widest part of the shell, is flattened, tubercular or granular, and furnished with undulating rays. These rays are the interstices of the projections made by the chambers of the last turn of the spiral.
The opening of the shell is that of its last chamber; it is marginal, trigonal, and seems inverted or directed towards the base. The transverse partitions which separate the chambers are directed like rays towards the centre or axis of the shell; so that the chambers are slightly conical.
[Lamarck 1804 emend Reuss 1866, original text]: Die Gattung wird hier in viel engerem Sinne genommen, als es bisher geschah. Sie umfasst nur jene Formen mit spiralem ungleichseitigem, meistens kreiselförmigem Gehäuse, deren Kammern ringsum durch selbstständige Wandungen geschlossen sind, so dass die Kammersepta aus zwei an einander liegenden Lamellen bestehen, welche verschiedenartig entwickelte canalartige Interseptallücken zwischen sich lassen. Zwischen diesen weit höher organisirten, echten Rotalien und den bei den Globigerinideen abgehandelten Gattungen, die durchzehends einfache Kammerscheidewände besitzen, findet mithin ein sehr wesentlicher Unterschied statt, der uns nicht nur berechtigt, sondern nöthigt, beide in verschiedene Familien zu versetzen, auf gleiche Weise, wie die durch dasselbe Kennzeichen von einander abweichenden Gattungen Pullenia und Nonionina.
[Google Translated from German]: The genus is taken here in a much narrower sense than previously. It includes only those forms with spiral, unequal-sided, mostly top-shaped shells, whose chambers are enclosed on all sides by independent walls, so that the chamber septa consist of two adjacent lamellae, leaving variably developed canal-like interseptal gaps between them. There is therefore a very essential difference between these much more highly organized, true Rotalia and the genera discussed in the Globigerinidae, which possess ten simple chamber septa, which not only justifies but compels us to place both in different families, in the same way as the genera Pullenia and Nonionina, which differ from each other by the same characteristic.
[Lamarck 1804 emend. Davies 1932]: Judging from its type species, Rotalia trochidiformis, the essentials of this genus appear to be as follows:
Test calcareous and coarsely tubulated. Its shape varies from stoutly lenticular to convex on one side and flat on the other. Its structure is trochoid, all the whorls being seen on the upper surface, and the last whorl only on the lower surface. The spire is multilocular and single throughout. The spiral chambers are separated by double septa, radially disposed, and formed by the puckering upward of the chamber floor. The pylome is single and elongated, and traverses the radial septum where it abuts against the preceding whorl.
The whorls are typically enveloping (as in Nummulites Lamarck) on the upper surface, and probably on the lower surface as well, at first. They eventually part, however, on the lower surface of the test, where the chamber wall is characteristically very thin. This lower wall of the chamber develops transverse septa as well as radial ones, each transverse septum starting from the rear part of the chamber and passing forward, with an inclination toward the centre of the test, so as to separate the inner portion of the chamber from the rest of it. The portion thus separated off constitutes the “astral lobe” of Carpenter and Brady.
In the type species, the upper surface of the test remains smooth throughout life, but the lower surface progressively develops tubercles and short pillars, irregular in character, and generally limited to the level of their own respective whorls, which soon become very numerous and crowd the whole central parts of the test, including the region of the astral lobes. This seems to indicate that the astral lobes belong to the umbilical parts of the test rather than to the spiral region where the sarcode is mainly accommodated.
(I am not inclined to stress pillars as a generic character in this form – as they are in Dictyoconoides and Lockhartia – until I have seen whether pillars accompany astral lobes in other species besides Rotalia trochidiformis. The study of Nummulites shows that pillars can be a very variable quantity within a genus, and the chamber structure of this form seems to me to be more important than its pillars. Its astral lobes seem to link it to Asterigerina and Amphistegina.)
Rotalia is thus distinguished from Dictyoconoides by the single nature of the spire; and from both Dictyoconoides and Lockhartia by the nature of its lower chamber wall, which penetrates deeply into the umbilical region of the test and there develops the lateral chambers herein called “astral lobes”.
[Lamarck 1804 emend. Smout 1954]: The test is built of radially fibrous calcite, laminated in the manner typical of the super family Rotaliidea. The spire is simple and trochoid; the cortical chambers simple, evolute dorsally and partly involute ventrally. There are no astral lobes, ventral chamberlets or umbilical cavities. The dorsal surface has perforate thickening. The ventral surface shows a whorl of chambers, sometimes partly obscured by thickening, with an umbilical plug that is split up by anastomosing fissures into pillars. The fissures are closed higher up by secondary deposits and an umbilical canal runs under the cortical chamber layer, receiving tributary canals from umbilical apertures of the cortical chambers. These are slits at the inner side of the chamber. There is no other canal system in Rotalia trochidiformis (Lamarck) [Rotalites trochidiformis, 1804]. In other species, fissures or canals are present in the septa (Carpenter, 1862, Introd. Foram., p. 214; Hofker, 1927, Siboga Exped., Monogr., no. 4, pl. 21, fig. 2, etc.). Williamson (1853, Micr. Soc. London, Trans., ser. 2, vol. 1, p. 87) stated that apparent canals are really fissures in “Faujasina”, a Recent species of Rotalia. The margin is not perforate and this gives a distinctive appearance to it. Family Rotaliidae. [See also Rotalia trochidiformis (Lamarck), emend. Smout, 1954.]
[Lamarck 1804 emend. Lévy, Mathieu, Poignant, and Rosset-Moulinier 1986]: Test free, trochospiral, biconvex; periphery subacute; spiral side strongly convex and coarsely perforate; umbilical side moderately convex and partly perforate; umbilical end of each chamber (folium) separated from peripheral part of chamber by foliar slit; central part of umbilical face studded with various-size granules; aperture interiomarginal extending from umbilicus to periphery; supplementary openings, one sutural, and other corresponding to foliar slit; existence in every chamber, including last one, of imperforate proximal wall (paries proximus) partly adherent to septum on peripheral side, partly separate and bending forward to umbilical face without joimng previous coil, and isolating foliar chamberlet; paries proximus forming fold around foliar slit in its free part; septum secondarily double.
Structural features. – (Pl. 1, figs. 4, 8-9, 12; Lévy, et al., 1986, op. cit.). The external morphology and internal structure of Rotalia trochidiformis (Lamarck) [Rotalites trochidiformis, 1804] are described in detail and illustrated in Lévy, et al. (1980 [sic; ?1982, op. cit., pp. 34, 35, pls. 1, 2]).
External morphology. – The main architectural features are the imperforate folium, often joined together by their umbilical border, separated from the main part of the chamber by the foliar slit, and the granules of the umbilical side. The various-sized granules are more developed on the older chambers. Their genesis is complex; they develop on the one hand from the progressive transformation of the foliums, and on the other hand from the transformation of the folded sutural borders. The deep sutures have been termed “fissures” by some authors (Smout, 1954, Lower Tertiary foraminifera of the Qatar Peninsula. London: British Museum (Natural History); Drooger, 1960, K. Nederl. Akad. Wetensch., Proc., ser. B, vol. 63, no. 4; Parvati, 1971, K. Nederl. Akad. Wetensch., Proc., ser. B, vol. 74, no. 1) as well as intergranular furrows (Parvati, 1971, loc. cit.).
Internal structure. – As in Discorbis and Trochulina [see Discorbis Lamarck, emend. Lévy, Mathieu, Poignant, and Rosset-Moulinier, 1986; and Trochulina d’Orbigny, emend. Lévy, Mathieu, Poignant, and Rosset-Moulinier, 1986], we have recognized the existence of a paries proximus. It splits off from the septum, bending forward dividing the chamber into two parts. Below the folium it appears as a plate with a free denticulate border which folds up, forming a curl in the foliar chamberlet. The groove which is created opens externally through the foliar slit. The paries proximus is a continuity in its distal part with the apertural face of the chamber. Therefore, the separation between the chamber and the foliar chamberlet is complete in every chamber. The paries proximus was termed the tooth-plate by Hofker (1951, Archives Néerl. Zool., vol. 8 (1947-1951), pt. 4; 1971, Natuurh. Genoot. Limburg, Publ., vol. 21, nos. 1-3) and Reiss and Merling (1958, Israel, Geol. Survey, Bull., no. 21), and umbilical flap by Parvatie (1971, loc. cit.). All these authors distinguish its proximal part as a septal flap.
Extra details from original publication
I confess that I find it difficult to follow van Rijsinge. On page 122 of his paper (1930, op. cit.), he states that, in the family Rotaliidae, this canal system is shown by “Rotalia alone”; but in the very next line he states that “the family of the Calcarinidae also shows this characteristic.” Within the latter family, he then tells us that “the genera Calcarina, Baculogypsina, Arnaudiella, and Pellatispira…have a typical rotalid canal-system” and he further states that this same canal system is also “typically shown” in the Polystomellidae (p. 123). He then remarks that “the family of the Rotaliidae thus” (sic) “includes the subfamilies Rotaliinae, Calcarininae and Polystomellinae.” So apparently his Calcarininae belongs both to his Calcarinidae and to his Rotaliidae, unless he means that he would remove it from the one to the other. In any case, it would seem that Rotalia is not, after all, the only genus of his “Rotaliidae” to possess this system; and if whole subfamilies with their included genera can thus possess it and still remain distinct, it is difficult to see why the discovery of such a system in Dictyoconoides should force us to regard that genus as identical with Rotalia.
I am also very doubtful as to the existence of this (umbilical) canal system either in Dictyoconoides or in Rotalia, although it may exist in certain species which Hofker and others have (as I believe, wrongly) referred to Rotalia. As regards Dictyoconoides, I have never seen such a system indicated in any section, or photograph of a section, made by myself or by anyone else; it appears only in two drawings (tfs. 5 and 12; I omit his tf. 6, since it represents a branch passing down a septal face from the whorl junction above; I have myself seen and photographed such markings, but they are traceable to the cortical suture itself and apparently have nothing to do with an umbilical system) published by van Rijsinge (1930, loc. cit.). Apparently this umbilical canal has, even by van Rijsinge, never been seen in meridian sections (and his drawings of meridian sections show no trace of it), which is rather remarkable. Can he have mistaken some parasitic borings for canals? Douvillé (1930, Soc. Géol. France, Livre Jubilaire, vol. 1, pp. 257-262) has shown how such mistakes can be made, and it seems extraordinary that the vast majority of thin sections should show no trace of this canal system if it really existed. What is more, there seems to be no function for a canal system lying along the umbilical line of open chamber mouths. Anything in the nature of a tube across this would not facilitate communication but block it, and such an obstruction would inevitably be seen in thin meridian sections.
Incidentally, van Rijsinge makes no attempt to prove that any other rotalid form possesses the remarkable intercalary whorls of Dictyoconoides; and although he (op. cit., p. 130) emphatically rejects the idea that secondary chambers can exist in the umbilical region of Dictyoconoides, and draws a figure (op. cit., pl. 5) of this region which represents it as containing only an open framework of crossed rods, he nevertheless declares (op. cit., p. 135) that Dictyoconoides possesses a closed umbilicus.
His arguments are not easy to follow; and since he does not discuss the question of type species, there can be no finality about his paper. Apparently Nuttall and Brighton (1931, Geol. Mag., vol. 68, no. 2, pp. 54-56), who refer to his article, cannot accept his proposed indetification, although their reasons for rejecting it seem to me rather indefinite. They merely state that Dictyoconoides seems to them a more specialised form than Rotalia, with a more restricted stratigraphical range (Nuttall and Brighton, 1931, op. cit., p. 55). That may well be so; but where – if that is all – are we to draw the line between the two genera?
The genotype of Rotalia. – It seems clear that, in order properly to compare Dictyoconoides with Rotalia, we must first determine the type species of the latter. This I now propose to do. The literature of the subject takes us back to the year 1770, when Guettard described and figured a certain “Hélicite rayonnée” (Guettard, 1770, Mém. diff. parties Sci. et Arts, vol. 3, p. 432, pl. 13, figs. 11-13, 22). It was apparently a lenticular form – perhaps a small Nummulite with mammillated centre and radiating filaments. Thirty-one years later, Lamarck described a new genus, to be known as Rotalites [see Rotalites Lamarck, 1801]. As representing this genus he quoted a “Fossile de Grignon”, to be seen in the “Cabinet du C. Defrance”; and he referred the reader to Guettard’s “Hélicite rayonnée” for figures of the species, to which he gave the name Rotalites tuberculosa.
It is not easy to identify this form now, since it is difficult to say what specimens were referred to. It seems unlikely that any specimens in Defrance’s collection were the actual ones figured by Guettard thirty-one years before. We cannot even be sure that they belonged to the same species or genus, for Guettard noted no such dissimilarity between the two sides of his “Hélicites” as Lamarck notes between the upper and lower surfaces of his Rotalites. Hence all that we can say is that Lamarck saw a resemblance between Guettard’s figures and the upper aspect (only) of some fossils which he called tuberculosa. It is improbable that we will ever identify the form on so poor a clue as that. (Professor Bigot tells me (letter of 12/5/1932) that no specimens in Defrance’s collection are labelled Rotalites tuberculosa.)
Three years later (1804) Lamarck for the first time published the name Rotalia as a generic designation. He identified this term to some extent, however, with the previously published Rotalites, since the forms to which he applied it were all fossil ones, and the convention of the day allotted names ending in “ites” – like “Nummulites” to genera supposed to be extinct. Under this designation Lamarck described four new species, namely Rotalites trochidiformis, Rotalites lenticulina, Rotalites depressa, and Rotalites discorbina, as included in the genus, which he now defined (Lamarck, 1804, op. cit., p. 184) as being represented by:
“…très-petites coquilles en spirale orbiculaire, convexes ou un peu coniques on dessus, dont les tours sont contigus et distincts, et dont la base, qui est la partie la plus large de la coquille, est aplatie, tuberculeuse ou granuleuse, et garni de rayons onduleux. Ces rayons sont les interstices des saillies que font les loges du dernier tour de la spirale.
L’ouverture de la coquille est celle de sa dernière loge; elle est marginale, trigone, et semble renversée ou dirigée vers la base. Les cloisons transversales qui séparent les loges sont dirigées comme les rayons vers le centre ou l’axe de la coquille; en sorte que les loges sont légèrement coniques."
It is clear that this generic description is different from the last. The shell is here described as being granulated and having radiating lines (formed by the depressions between successive chamber swellings) on the lower surface of the test, which shows the last whorl only; while the upper surface is more convex, apparently devoid of granules, and shows all the whorls in close contact with each other. Formerly it was the upper surface which was said to be granulated, and the lower one to be smooth. We also see that the species tuberculosa is no longer mentioned. What becomes of it is not clear. We never hear of it again.
Of the four species which are here described, only two, Rotalites trochidiformis and Rotalites discorbula, are figured by Lamarck (1806, Ann. Mus. National Hist. Nat., vol. 8, p. 387, pl. 62, figs. 8a-b, 9a-b). These figures, together with the descriptions, also make it clear that Rotalites trochidiformis is the only one of the four species which agrees with the generic description in possessing a granulated lower surface. It seems obvious, therefore, that R. trochidiformis was the species upon which the generic description was mainly founded. It is pre-eminently the representative of the genus, as now redescribed and given the alternative name of Rotalia.
Lamarck’s figures [see Rotalites trochidiformis Lamarck, 1804] show a form with smooth upper surface displaying a spire of several whorls, and a granulated lower surface dissected by about ten radiating lines and bounded by a smooth outer rim. It is noticeable that the last chamber shows a constriction halfway between the centre and the periphery; although Lamarck makes no comment on this, it apparently corresponds to something seen by the artist.
Defrance [Blainville] (1816-1830, Dict. Sci. Nat., Planches, pt. 2, pl. 14, figs. 3, 3a-c; pl. 19, figs. 1, 1a-c) and Blainville (1825, Manuel de Malacol., p. 391, pl. 6, figs. 3, 3a-c; pl. 10, figs. 1, 1a-c) also figured this species, and in greater detail. They show that the granules on the base tend to align themselves along the margins of the furrows between successive whorls (a character subsequently remarked on by Lamarck [Deshayes]* (1832, Ency. Méth., vol. 3, p. 912), who says that the granules give these furrows the appearance of little bushes – “petits arbuscules”). [The author of the text of Volume (1832) of the Encyclopédie Methodique is Deshayes; Lamarck is the author (or responsible for) some of the accompanying plates (1816, Tableau Encyclopedique et Methodique, pt. 32); see Dodge 1947, Jour. Pal. vol. 21, no. 5, pp. 484-486. Lamarck, therefore, is not responsible for what was published in Volume 3 (1832).] Defrance [Blainville] also shows the existence of some irregularity about halfway between the centre and the periphery of the test, for the furrows are not continuous, but dislocated at midradius.
It seems clear that Rotalites trochidiformis is the species which pre-eminently represents Lamarck’s genus Rotalia. It is the first to be described and figured under that heading; and the only species mentioned at the time which fully matches the original description of the genus. It is true that the term Rotalia was at first regarded as a mere equivalent of Rotalites, and that another species had previously been named as representing Rotalites; but the latter species had never been recognisably indicated, and its own author had not only abandoned it but had also completely revised the generic description which he had drawn up to suit it. The revised generic description, its alternative name of Rotalia, clearly applies to the species trochidiformis and not to tuberculosa.
We consequently find that all writers during the next few years, while completely ignoring the ill-fated species tuberculosa, treat trochidiformis as the leading representative of the genus Rotalites. Defrance [Blainville] (1824, Dict. Sci. Nat., vol. 32, p. 187) and Blainville (1825, Manuel de Malacol., p. 391) presently show a tendency to replace the other three species (i.e., lenticulina, depressa and discorbula) by new ones; d’Orbigny (1826, Ann. Sci. Nat., vol. 7, pp. 272-276) does so very emphatically, retaining trochidiformis alone of the species described by Lamarck, but adding to it no less than fifty-four species of living foraminifera. Since he thus maintained that the genus was still in existence, d’Orbigny referred to it under its alternative name of Rotalia. Similarly, after Lamarck (1822, Hist. Nat. Anim. sans Vert., vol. 7, p. 617) quoted trochidiformis as the sole example of the genus Rotalites, [Deshayes]* subsequently (1832, Ency. Méth., vol. 3, pp. 912-913) added five of d’Orbigny’s living species to it and called it Rotalia trochidiformis. [The author of the text of Volume (1832) of the Encyclopédie Methodique is Deshayes; Lamarck is the author (or responsible for) some of the accompanying plates (1816, Tableau Encyclopedique et Methodique, pt. 32); see Dodge 1947, Jour. Pal. vol. 21, no. 5, pp. 484-486. Lamarck, therefore, is not responsible for what was published in Volume 3 (1832).] By Lamarck’s own* action, therefore, in subsequently ignoring – or else transferring to other genera – all other species originally included in Rotalites or Rotalia, and finally discarding the very term Rotalites, it is made still more clear that the only species which can be regarded (under modern rules of zoological nomenclature) as the type of Rotalia is trochidiformis. [Ed. note: “Type by elimination” is a Recommendation, not a Rule (International Rules of Zoological Nomenclature, Art. 30).]
It follows, therefore, that, provided this species can be identified, we must repudiate all efforts made by subsequent writers to replace Rotalia trochidiformis by species which they have considered to be better types of what they would call Rotalia – species which were either unknown to science when Lamarck proposed that genus or else were ignored by him when proposing it.
Among these actions which cannot be endorsed we may mention that of d’Orbigny, who, in his “Prodrome” (1850, Prodrome Pal., vol. 2, p. 407), removed Rotalia trochidiformis from the position of priority which he had formerly (1826, op. cit., p. 272) allowed it among the representatives of Rotalia, and gave first place to one of his own species which he had formerly placed in a different subgenus. Far more reprehensible was the action of Carpenter, Parker and Jones (1862. Introd. Study Foram. pp. 203-204), and then of Brady (1884, Rept. Voy. Challenger, Zool., vol. 9, pp. 641, 702, etc.), who (in 1862 and 1884, respectively) removed Rotalia trochidiformis altogether from the genus of which it was the first representative, and treated it as a subordinate member of a new genus, Discorbina [Parker and Jones, 1862]; while they proposed that another species, Rotalia beccarii (Linné) [Nautilus beccarii, 1758], of a generically different type, should be regarded as the true representative of Lamarck’s Rotalia. To endorse such an action would perpetuate both a synonym and a homonym, and we seem compelled to set our faces against it. In any case, when otherwise excellent authorities like Hofker (1927, Siboga-Exped., Monogr., no. 4, pp. 34-42) follow Carpenter and Brady in treating other species as the true types of Rotalia, it must be realised that the characters which they impute to Rotalia are not those of the type species of Rotalia; they are the characters of species which ail authorities seem to have agreed in regarding as generically distinct from Rotalia trochidiformis.
Before beccarii (or any other species) can be treated as even inclusive among the Rotalia (s. str.), it must be shown to be generically identifiable with Rotalia trochidiformis. If not so identifiable, it must be referred to some other genus; perhaps beccarii itself should be returned to d’Orbigny’s genus Turbinulina, of which d’Orbigny quoted it as a leading type.
Thus we see that the canal system, on which Hofker and van Rijsinge lay such stress when writing of Rotalia, cannot after all be regarded as a characteristic of Rotalia; for Carpenter, Brady, and Hofker himself all agree that such a system is not found in Discorbina – to which genus they have relegated Rotalia trochidiformis.
Material examined. – It now remains for us to see what exactly are the characters of Rotalia trochidiformis. The following material, registered as Rotalia trochidiformis, was kindly lent to me for examination by the Keeper of Geology, British Museum (Natural History): Thirty specimens from Chaussy (see localities of collection below), from the Jones collection (1881); also fifteen other specimens from Chaussy and twelve from Parnes, from other collections. Douvillé, who most kindly searched the Paris museums for available specimens, sent me ten from Chaussy (from Bezangon’s collection at the École des Mines), and twenty-three from Hauteville (also from the collections at the École des Mines). Bigot, the Director of the Muséum d’Histoire Naturelle at Caen, most kindly capped my opportunities for examining this species by sending, for my inspection at the British Museum, the original type specimens of Lamarck, being thirty individuals from Grignon, in the Defrance collection at Caen. The totals examined (apart from a number of less well accredited or preserved specimens at the British Museum) have thus been thirty from Grignon (type material), fifty-five from Chaussy, twelve from Parnes, and twenty-three from Hauteville; total 120. With very few exceptions, these all seem to me to belong to the same species, although the Hauteville forms show some minor differences from the others, as detailed below [see Rotalia trochidiformis (Lamarck) var. hautevillensis Davies, 1932]. Having been allowed to section a number of the specimens from the British Museum and the Ecole des Mines, I have been able to study the internal structure of the species as well as its external aspect.
Localities of collection. – The little villages of Grignon, Chaussy, Parnes, and Hauteville, although well known in French geological literature, are seldom shown on even the largest topographical maps of France. I therefore give their respective coordinates below. These coordinates have been very kindly checked for me by Bartholomew of the Geographical Institute, Edinburgh (letters of 22 and 26/1/32). The meridians are Greenwich ones.
| Grignon...... | lat. 48°51’ N., long. 1°57’ E. |
| Chaussy...... | lat. 49°07’ N., long. 1°42’ E. |
| Parnes........ | lat. 49°13’ N., long. 1°45’ E. |
| Hauteville... | lat. 49°25’ N., long. 1°28’ E. [W.] |
The first three are in the Paris basin, to west and northwest of Paris (Grignon being a few miles west of Versailles, and the other two near Magny). Hauteville is in the Catentin, near Valognes, a good deal farther west. Lamarck, Defrance, and d’Orbigny, the chief early students of Rotalia trochidiformis, all mention Grignon (the type locality) and Valognes, or Hauteville near Valognes, among the chief places where the species can be collected. Lamarck and d’Orbigny also mention Parnes. Chaussy, Douvillé tells me (letter of 10/1/1932), is a classic locality for the middle Lutetian; it is near Parnes. The beds at Grignon, Chaussy, and Parnes all seem to belong to the same horizon, and the Rotalia trochidiformis specimens from them are indistinguishable from each other. I understand from Douvillé that the Hauteville beds are of about the same age as the others, but include several horizons, of which the highest probably reaches the Auversian. The specimens from there may accordingly belong to more than one zone. As Douvillé also remarks, the middle Eocene sea, entering the Paris basin from the west, would have been deeper to the west; and many species are found there which do not reach the Paris basin. So it is natural enough that a different race or variety of Rotalia trochidiformis should be found in the west.
The Defrance specimens. – These constitute the great bulk of the original type material of this species, and are remarkably well preserved, considering their age. The set has been photographed for this paper [see Rotalia trochidiformis (Lamarck), emend. Davies, 1932], so a brief description will be sufficient here. As Cushman (1927, Cushman Lab. Foram. Res., Contr., vol. 3, pt. 3, pp. 140-141) recorded, there are thirty specimens in the set, all mounted on one slide, which is labelled R. trochidiformis in Lamarck’s own handwriting. Cushman’s figures, however, which are drawings and not photographs (Cushman, 1927, Cushman Lab. Foram. Res., Contr., vol. 3, pt. 2, pl. 24, figs. 5-7b). cannot be identified with any particular specimens on this slide, and are probably sketched from other material, since they seem to have been published before he saw this slide (vide his remarks on p. 122). In any case, I believe that my illustrations are the first photographs to be published of this particular set of specimens. As the general photograph (pl. 3, fig. 1) [see Rotalia trochidiformis (Lamarck), emend. Davies, 1932] shows, the specimens are arranged in two rows – thirteen in the upper and seventeen in the lower. They are graded in size, and show the progressive development of granules, etc. Practically all the specimens belong without doubt to the same species (a few, showing upper surfaces only, may be questioned; and one – second from the left in the lower row – which has sixteen or seventeen chambers instead of about eight in its last whorl at a diameter of 1.4 mm., is almost certainly an alien). With true judgment, most of the specimens have been mounted to show the lower surface, which is much the most important one in dealing with this species. Some dirt, which I dared not try to remove, appears on all the specimens, but shows less than expected in the photographs. The chief damage suffered by the collection has been due (as Dr. Thomas pointed out to me) to the use of a very powerful gum to mount the specimens. This gum has, in shrinking, torn away the upper surface of all the larger specimens. This is regrettable, but incidentally shows the perfectly enveloping nature of the whorls, which can be peeled off so neatly as separate coats. This removal of the outer layers exposes the perforations on the surfaces of the inner ones. These are of much the same size as the perforations of the lower surfaces of the tests, which still appear clearly under the microscope, mostly unchoked in spite of their minute size and one and a quarter centuries’ exposure to the air. [Lamarck’s collection of fossils (Defrance Collection) was destroyed at Caen during World War II, fide Maync, 1952, Contr. Cushman Found. Foram. Res., vol. 3, pt. 2, p. 36.]
Lamarck’s specimen. – Besides Defrance’s collection was Lamarck’s own, which he mentioned as also containing Rotalia trochidiformis. This collection is now in the Muséum d’Histoire Naturelle at Geneva, and it has been excellently photographed and described by Favre (1918, Cat. Illus. Coll. Lamarck, pt. 6, pl. 2, figs. 12a-c). Apparently there were once three specimens of Rotalia trochidiformis in Lamarck’s collection, but only one now remains. It is fairly large (3 mm. diameter) and is labelled trochidiformis in Lamarck’s own handwriting. It is, however, considerably damaged, and its lower surface has been filed down and polished – an operation which has obliterated the important external features of the middle of the base. Sufficient indications remain to convince me that the specimen is a true Rotalia trochidiformis; but it would be impossible to study the species properly from such a mutilated fragment, and it is fortunate that the Defrance collection contains so many and better preserved representatives of this species. Favre has, however, not only consented (letter of 22/12/1931) to my reproducing his photographs of this specimen, but has also most kindly sent me his original prints. I have therefore been able to enlarge them from five diameters to ten, in order to bring out all the detail possible regarding this specimen [see Rotalia trochidiformis (Lamarck), emend. Davies, 1932, pl. 2, fig. 8].
Main results of examination. – Examination of the types confirms the general accuracy of Lamarck’s and Defrance’s descriptions and figures. It also brings out the importance of a feature which they overlooked in their descriptions but vaguely indicated in their illustrations, namely, the “astral lobes” which Carpenter, Parker and Jones (1862, op. cit., p. 204) and Brady (1884, op. cit., pp. 641-642) attributed to Discorbina (the genus in which they placed Rotalia trochidiformis). These lobes are marked off in Rotalia trochidiformis by a transverse furrow (fold or crease) across each chamber floor. This furrow divides the chamber into two portions, an outer and an inner one; and it was the inner portion (generally more turgid than the outer) which those authors called the “astral” (or “asterigerine”) lobe, since the inward inclination of the furrow gave each lobe a pointed appearance (see tf. 4).
Viewed from below, these lobes appear in stronger relief (owing to their turgid character) than the main or outer portions of the chambers. Internal sections show that the lobes are crowded with pillars, and so are virtually part of the umbilical region of the test, which is thus deeply invaded by the lower chamber wall in a manner never seen in Dictyoconoides Nuttall or Lockhartia Davies. Indeed, it is only in the later whorls of Rotalia trochidiformis that the lower chamber wall seems to be parted at all; for the first whorl or two it seems to pass completely across the umbilicus, although it becomes very thin and irregular while doing so.
Pillars, which are rare or imperfectly developed in early whorls, are always confined to the lower surface of the test in Rotalia trochidiformis. They begin to form along the edges of the astral and septal furrows (see tf. 4). These furrows first become crenulated or wrinkled, then granulated, and soon crowded with granules, which spread therefrom over the whole base of the test (excepting the marginal band, which is always smooth) until both furrows and lobes may finally be lost to sight under them. A specimen whose base is thus crowded over with pillars and granules may appear deceptively like Lockhartia; but an axial section will show the profile of the astral lobes, formed by its deeply penetrating lower chamber wall (see tf. 5).
Selection of lectotype. – No individual specimen has yet been selected as the type of Rotalia trochidiformis. Owing to its condition, it would not be justifiable to select the very damaged specimen in the Lamarck collection, when so much better ones exist in the equally well certified and original Defrance material. Of the latter, after careful consideration of all points, I propose to select the fourth specimen from the left, of the lower row (containing seventeen), as the lectotype [see Rotalia trochidiformis emend. Davies, 1932]. It is one of the smaller specimens, which is regrettable in itself, but I select it for the following main reasons: 1) It is the largest intact specimen in the collection, all larger ones having been torn open by the powerful gum applied to them; 2) it shows the essential characters of the type very clearly; in larger specimens the astral lobes tend to become obscured by the increasing mass of granules; this specimen shows clearly both the characteristic lobes and also the characteristic preliminary disposition of the granules.
[Lamarck 1804 emend. Smout 1954]: Remarks. – Davies (1932, Roy. Soc. Edinburgh, Trans., vol. 57, pp. 408-424) established Rotalites trochidiformis Lamarck, 1804, as the type species of Rotalia, and gave reasons for using the name Rotalia in preference to the older name Rotalites. Davies depicted the type species accurately, but misinterpreted the internal structure. He stated that Rotalia has astral lobes to the cortical chambers. This is not so, and his generic definition is therefore incorrect. The umbilical canal system was recorded by Hofker (1927, op. cit., p. 35) for other species, and by Barker and Grimsdale (1937, Jour. Pal., vol. 10, p. 167) for Rotalia trochidiformis. Little attention has been given to the taxonomic importance of the double septa of Rotalia, although these are often mentioned, e.g. by Carpenter (1862, op. cit., p. 214), but no distinction in respect of this character has been made from the rather similar genera Discorbis, Asterigerina, Pseudovalvulineria, etc. Hofker (1951, Siboga Exped., Monogr., no. 4b, pp. 491-502) still makes little use of this distinction. In his discussion of Streblus Fischer, 1817, he attributed by implication the same characters to Rotalia as are given here, but his taxonomy is invalid because he uses Rotalia schroeteriana Parker and Jones, 1862, as the type species and, erroneously thinking that Rotalia trochidiformis has a different structure, removes that species from the genus Rotalia. This is a nomenclatural impossibility. Hofker separates Streblus (type species Nautilus beccarii Linné, 1758) from Rotalia because no secondary deposits are formed to block the umbilical fissures and leave a spiral canal. Frizzell and Keen (1949, Jour. Pal., vol. 23, pp. 106-107) have pointed out that Ammonia Brünnich, 1771, Hammonium Fichtel and Moll, 1798, and Turbinulina Risso, 1826, all have the type species Nautilus beccarii. Ammonia is the senior name (see Winckworth, 1945, Bull. Zoom. Nomencl., vol. 1, pt. 5, p. 116; and conclusions of the Committee on Nomenclature of the International Zoological Congress, 1950).
Barker and Grimsdale (1937, op. cit., p. 168) state that Rotalia has peripheral subsidiary chamberlets. This is not so. The cavities to which they refer are either peculiar to Rotalia mexicana Nuttall var. mecatepecensis Nuttall or are the tiny cavities that appear at the top of each septum in all genera of the Rotaliidea and are not a special character of Rotalia. They have no connection with the idea of astral lobes and are situated peripherally, not ventrally. Dimorphism is not usual in Rotalia.
[The following forms were explicitly included in the emended genus Rotalia Lamarck by Smout in 1954 (loc. cit.)]:
[Lamarck 1804 emend. Lévy, Mathieu, Poignant, and Rosset-Moulinier 1986]: Historical background. – In all foraminiferal classifications, Rotalia is the type of the Rotaliidae. Many species were formerly assigned to this genus because of Lamarck’s inaccurate original diagnosis. It is currently restricted by the erection of some other genera, and the number of species which are really attributed to it is considerably reduced.
The historical background has been explained in a previous paper (Lévy, et al., 1982, Géol. Méditerranéenne, vol. 9, no. 1, pp. 35-40) and at that time, we gave a comparative table of the structural features of the genus, which have received according to the authors, various names.
Remarks. – Loeblich and Tappan (1964, in: Moore (Ed.), Treatise on invertebrate paleontology. New York: Geol. Soc. Amer., pt. C, Protista 2, vol. 2; 1984, Micropaleontology, vol 30, no. 1) define the characteristic features of the Rotaliidae as the existence of radial, sutural and subsutural canals. We agree with the opinion of Reiss and Merling (1958, loc. cit.) who consider that the term “canal-system” refers only to intralamellar structures. Therefore, a canal-system in Rotalia trochidiformis does not exist but only interior intralocular spaces. The “fissures” of Smout (1954, loc. cit.), Drooger (1960, loc. cit.), Parvati (1971, loc. cit.) are merely deep sutures and not canals, and the succession of communicating foliar chamberlets does not constitute a canal-system. This is in disagreement with the opinions of Glaessner (1945, Principles of micropaleontology. Carlton, Victoria: Melbourne University Press) and Smout (1954, loc. cit.), but in keeping with Reiss and Merling (1958, loc. cit.). In the same way, the term spiral-canal of Parvati (1971, loc. cit.) and Hofker (1971, loc. cit.) is inaccurate.
Editors' Notes
Davies, L. M. (1932). The genera Dictyoconoides Nuttall, Lockhartia nov., and Rotalia Lamarck: Their type species, generic differences, and fundamental distinction from the Dictyoconus group of forms. Transactions of the Royal Society of Edinburgh. 57 [1934](pt. 2, no. 13): 397-428. gs Lamarck, J. B. (1804). Suite des memoires sur les fossiles des environs de Paris. Annales du Museum National d'Histoire Naturelle, Paris. 5: 349-357. gs Lévy, A., et al. (1986). Discorbidae and Rotaliidae: A classification to be revised. Journal of Foraminiferal Research. 16(1): 63-70. gs Reuss, A. E. (1866). Die Foraminiferen, Anthozoen und Bryozoen des deutschen Septarienthones. Denkschriften der kaiserlichen Akademie der Wissenschaften zu Wien. 25(1): 117-214. gs Smout, A. H. (1954). Lower Tertiary foraminifera of the Qatar Peninsula. British Museum, London. 1-96. gsReferences:
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Rotalia compiled by the bforams@mikrotax project team viewed: 18-7-2026
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