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Show • 1894.] ON SOME FORAMINIFERA FROM TRINIDAD. 647 4. On some Foraminifera from the Microzoic Deposits of Trinidad, West Indies. By R. J. L E C H M E R E GUPPY, C.M.Z.S. [Received August 27, 1894.] (Plate XLI.) §1. Introductory. A paper of mine ou the Microzoic deposits of Trinidad was read before the Geological Society of London on the 8th June, 1892, and published in the November 1892 part of the Journal of the Society. Subsequently I communicated to a local scientific society of Trinidad a notice on the subject. But in these papers I did not deal with the novelties I had discovered in these rocks. Having been prostrated by a most serious illness I was unable for a long time to follow up the subject; and when 1 did so m y work progressed but slowly. Hence 1 am only now in a position to make known some forms which appear to be new, and to bring forward some observations which may possibly throw light on the evolution of certain forms of the Foraminifera. The species of Foraminifera have possibly as definite a form as most other species of organic beings. The amount of variation among what are called the higher animals is very great, as is shown by the fact that in some cases a single natural species has been made into a dozen or more by naturalists. W e are not always acquainted with the limits of variation of a species, and we are often misled, or surprised and puzzled, by the occasional appearance and partial persistence of an embryonic condition which we do not understand ; for example, the exceptional appearance of a specimen of Fronclicularia or Nodosaria with a Cristellarian commencement. But in what are called the higher animals we are are not unfamiliar with the occurrence or persistence of what are known as embryonic characters. Such characters have thrown most valuable light upon the affinity and course of development of animals and plants. So they will probably do in the case of Foraminifera. § 2. On the Initial Stage of Frondicularia. The specimen exhibited (Plate XLI. fig. 7) might, by some rhizo-podists, be called Lacgena globosa. It is in all essential respects similar to the specimens figured under that name by Sherborn and Chapman (Journ. B. Microsc. Soc. 1886, pi. xiv. figs. 11,12). But m y impression is that it is none other than the initial chamber of a Polymorphina. Messrs. Parker and Jones, in a memoir on North- Sea Foraminifera (Ann. & Mag. Nat. Hist. ser. 2, vol. xix. p. 273, 1857), perceived that tbe primordial segment of Polymorphina resembled a Lagena1. They remark of specimens of this kind 1 See also the specimens figured by Reuss, ' Lagenideen,' pi. i. figs. 1-3. The figures of L. globosa in the ' Challenger' Report are true Lagena, and do not exhibit this form. |
