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|Pullenia lillisi Church 1941|
|Pullenia sphaeroides var. obliquiloculata Parker & Jones|
= Pulleniatina obliquiloculata
"The generic designation Pullenia is applied by Messrs. Parker and Rupert Jones to a minute form which has been represented by M. d'Orbigny (Modèles, No. 43) under the name of Nonionina sphaeroides, and has been subsequently described by him under the name of N. bulloides . It differs so widely from the ordinary Nonioninae (which we shall hereafter see to be low forms of Polystomella), and presents such features of approximation to Globigerina, as to justify its being ranked as an aberrant form of the group of which the latter is the type; whilst it is differentiated from all other forms at present known by characters that are of sufficient importance to justify its being ranked as a distinct genus.
The shell of Pullenia has a globose form, the distance between its two poles being nearly or quite as great as the diameter of the spire. It is formed of a series of segments following one another in a symmetrical or nautiloid spiral, the number of these segments in each turn of the spire being usually four or five; each whorl is normally invested by that which succeeds it, the chambers of the latter being prolonged on either side to the centre of the spire; and the last chamber is usually large, occupying about one third of the lateral aspect of the spire. The septal plane is a narrow crescent; and the aperture is a very elongated fissure, extending almost from one point of that crescent to the other. The segments are in general but slightly convex, without any considerable depressions at their junctions; but sometimes they are turgid or vesicular, and obliquely coiled, like the chambers of Globigerina; and it may then happen that they do not so far extend themselves over the preceding whorl as to conceal it, so that the whole spire remains visible . These minute shells are extremely glassy in their texture, and their pores are fine. They are among the smallest Polythalamia at present known; their diameter averaging 1-50 th and never exceeding 1/30 th of an inch.
Extra details from original publication
This type is related to Globigerina in the simplicity of its structure, and in the occasionally globigerine character of its chambers, as well as in the wideness of their aperture; whilst among true Globigerinae there are some forms which approach it in mode of growth. On the other hand, it is related to Nonionina in its plan of growth, and in the comparative fineness of its porosity.
Pullenia compiled by the pforams@mikrotax project team viewed: 21-9-2021
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