App. a.] Dr. PiTTON on the Strata below the Chalk. 33^} 



Fig. 13. Terehratula parvirostris. Imperfectly tetrahedral, rounded; beak small, sharp; 

 sides slightly produced and angular ; plaits numerous, angular ; eight or nine of them much ele- 

 vated in the front. 



Fig. 14. Terehratula prcelonga. Ovate, much elongated, gibbose ; front slightly elevated, 

 with a depression in its middle ; beak prominent, large ; surface smooth. The figure a. is from 

 a drawing by the Rev. G. E. Smith ; h, from another specimen, also found near Sandgate. 



Fig. 15. Lingulal truncata. Ovate, depressed, flattened most along the middle; front 

 straight. 



Fig. 16. Plcitrotomaria gigantea. {Trochus ; British Mineralogy, t. 403.) Conical, height and 

 breadth equal ; whorls slightly overlapping each other; sides straight; surface concentrically 

 striated. The transversely striated band proceeding from the deep sinus in the lip, which marks 

 the genus, is well preserved on a specimen seven inches in diameter, in the collection of Charles 

 Manning, Esq., who obtained it from near Hythe, after this plate was engraved. Some speci- 

 mens of this shell are so much changed by pressure as not to be above one inch high, while they 

 are three or four inches in diameter, with a sharp margin. 



Fig. 17. Jmmonites furcatus. Discoid, sides and front flat; inner whorls partly exposed ; 

 aperture with a square front, oblong, deeply impressed with the preceding whorl, lateral angles 

 truncated ; ribs not very numerous, thick, curved, many of them forked, passing at right angles 

 across the front. 



PLATE XV. 



Scaphites Hillsii*. General form obovate, compressed ; the inner whorls exposed, not touching 

 each other, but still curved into a regular volute, compressed, bearing numerous small, close» 

 rounded ribs : the outer whorl strikes off from the others, in nearly a straight line, to a con- 

 siderable distance, and then bends back so that the aperture nearly touches the preceding whorl, 

 furnished with ten or more distant, very prominent, sharp-edged ribs, which are most raised 

 upon the sides. Aperture nearly square, thin-edged, preceded by a short rib over the front; 

 Siphuncle small, close along the front, or outer margin of the whorls ; septa much sinuated, not 

 very close. The system of inner whorls occupies rather more than half the longest diameter of 

 the entire shell, which is about fourteen inches. 



Fig. 1. represents a specimen of the inner whorls, reduced to half the real diameter. A small 

 Exogyra was found attached to the inner margin of one of the whorls of this individual, showing 

 that there was always a space between it and the next whorl. 



Fig. 2. is drawn from a portion of an outer whorl, also half the natural size. The specimen is 

 irregularly flattened. 



Tlie above description has been made from several nearly entire specimens, obtained from the 

 vicinity of Maidstone after this plate was engraved, and now in the possession of Sir Philip Grey 

 Egerton, Mr. Bowerbank, and Mr. Sowerby. An outline, taken principally from Sir P. G. Eger- 

 ton's specimen, on a scale of one fifth of the original dimensions, is inserted in the plate at fig. 3. 

 Mr. Sowerby has also a specimen, from the same place, of a species nearly agreeing with this 

 one, but probably distinct : it is much larger ; and its system of inner whorls is free from radii 

 and undulations. 



* In the list at p. 128, this fossil is erroneously called Hamites; perfect specimens not having 

 been found, when that page was printed. 



