1852.] MORRIS — THANET SANDS FOSSILS. 267 



Ampullina subdepressa, d. sp. (not figured). 



Imperfect specimens of a shell (from Pegwell and Heme Bays) 

 have been obtained, which bear considerable resemblance to Globulus 

 {Ampullina) depressus, Lamk, sp., from Barton ; but the spire is not 

 so elevated, and the umbilicus is much more open ; it is possibly 

 only a local variety. 



Cristellaria platypleura*, n. sp. Plate XVI. fig. 12. 

 Diam. -jig^ inch. 



Testa ovata vel subcircularis, postice rotundata, antice angulata ; margo acutus, 

 crista pellucida instructus : loculi 9, plani, irregulariter arcuati, ultimus antice 

 excavatus ; suturae valde costulatae ; umbo densus, prominens ; apertura rotunda, 

 margine granulate. 



In a young state this Cristellaria is ovate, and has its cells more 

 regular, and the umbo and ribs less thickened and distorted. 



Cristellaria Wetherellii, n. sp. Length -^j inch. 



Testa oblonga, antice acuta, basi spu-aliter involuta, rotundata ; margo arcuatus, 

 acute anguJatus; loculi 12, laevigati, angusti, antici inferue marginati, ultimus 

 subconvexus ; suturae planse, pellucidae ; apertura rotunda, margine radiato. 



In the young state this Cristellaria is subovate, the umbo being 

 almost central ; but in the more advanced stage of growth, the cham- 

 bers having gradually left the spiral for an almost straight direction of 

 growth, the inner or inferior margins of the cells cease to join the 

 umbo, and the form of the shell becomes elongate. One old specimen 

 quite assumes the form of a Marginulina. 



The Cristellaria from Mr. Wetherell's collection, and belonging 

 to the London Clay, figured by Mr. Sowerby in the Trans. Geol. Soc. 

 2nd ser. vol. v. pi. 9. fig. 19, represents one stage of growth of this 

 species. 



RosALiNA Mari^, n. sp. Plate XVI. fig. 13. Diam. /^ inch. 



Testa suborbiculata, depressa, rugosa ; superne sex-lobata, vix umbilicata ; subtus 

 umbilico lato, aperturis subvalvulatis circumdato ; margo rotundatus ; loculi 6, 

 subconvexiusculi, irregulariter triangulati, ultimus antice valde convexus. 



PoLYMORPHiNA AMPULLA, n. sp. Plate XVI. fig. 14. 

 Diam. -^q inch. 



Testa subglobosa, laevigata, superne in rostro brevi producta, basi obtusa ; loculi 

 pauci, convex! ; suturae lineares ; apertiura rotunda, excentrica, radiata. 



[It is not at all improbable that Boys and Walker, as well as Mon- 

 tagu, have figured and described several of the Foraminifera of the 

 Thanet Sands of Sandwich as recent forms. — T. R. J.] 



* These new Foraminifera are described by Mr. T. Rupert Jones. 



