652 OK SOME FORAMINIFERA FROM TRINIDAD. [Xov. 6, 



closely embracing. Sometimes each successive chamber embraces 

 all the previous ones ; in other cases some of the initial chambers 

 are visible as indistinctly marked annular segments. A thread-like 

 ridge, like a flange, surrounds the sphaeroid in the direction of its 

 length. This ridge, which often appears to be double, expands at 

 the larger end of the test, and its two elements separating, leave 

 between them a fissurine aperture. This is an elongated narrow 

 opening between two pouting lips, the lips being a continuation 

 and extension of the ridge or flange. Many specimens show a 

 ridge at right angles to the longitudinal ridge ; but this is produced 

 by the breaking-away of the last chamber at the line of suture. 



This singular organism appears to differ in some essential 

 characters from any Foraminifer hitherto known, at least so far 

 as I have been able to find out. It varies in shape from an almost 

 perfect sphere to a sphasroid of very prolate shape, the initial 

 (aboral) end being sometimes a very rounded and blunt projection. 

 The longitudinal ridge is sometimes obsolete towards the aboral 

 pole, sometimes it is single, and occasionally it is triple, the two 

 lateral elements being the most raised. In shape the test resem- 

 bles a very round Glandulina, like G. obtusissima, Reuss (Tert. 

 Foram. Fauna, 1803, pi. viii. fig. 93 ; also G. globulus, figs. 94, 95), 

 or G. abbreviate, Xeug. (Sherborn and Chapman, London Clay 

 Foram., Journ. Microsc. Soc. • 18S6, pi. xiv. fig. 20), or a Lagena 

 like L. obtusa, Egg. (Reuss, ' Lagenideen/ 18G2, pi. vii. figs. 92, 93). 

 The test is hyaline, glistening, and very fine and close-grained in 

 texture. 



It has only been found in the Ditmpa-bed of Pointapier, Trinidad. 



EXPLANATION OF PLATE XLI. 



Fig. 1. Amphicoryne-forin of Xodosaria hispida, D'Orb., var. 



2. Cristellaria aculcata, D'Orb., var. A form found abundantly in the 



Ditriipa-bed of Pointapier, Trinidad. Closely allied to C. wetherellii, 

 Jones, and C. fragaria, Giimb. Compare also Margimdina cristella- 

 rioides, Giimb. For comparison with fig. 1. 



3. Frondicularia complanata, Defr. Flabelline variety showing Cristel- 



larian initial portion. 



4. Frondicularia alata, D'Orb. (complanata, Defr.). Specimen showing 



(a) Cristellarian initial portion, and (b) portion reproduced after loss 

 by fracture of the original oral portion. 



5. Frondicvlarin flabclliformis. n. sp. Usual form. In many specimens 



the ends of the chambers project more than is shown in tins drawing 

 G. Frondicularia flabelliformis, n. ap. A thicker and stouter form thnn 

 the preceding. This may be compared with F. spissa, Terquem 

 (Rupert Jones, ' Monthly Microscopical Journal,' 1870, pi. cxxviii. 

 fig. 24). 



7. Initial segment of Polymorphina, comparable with Lagcna globosa, Mont. 



8, 9. Specimens showing the development of Frondicularia from a 



Polymorphina segment. These may be compared with Flabellina 

 jjonderosa and triqnetra, Terquem (Rupert Jones, ' Monthly 

 Microscopical Journal,' 1876, pi. cxxviii. figs. 25, 26). 



10. Stilostomella rugosa, n. sp. A specimen with a protuberant neck. 



11. The same. A specimen with a less protuberant neck. 



12. Ellipsoidina subnodosa, n. sp. 



13. Ellipsoidina e.vponens, Brady, MS. 



