266 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 21, 



striated ; the beaks somewhat acute, and recurved over the lunule, 

 which is elhptical and smooth ; the Ugamental area excavated ; the 

 margins of the shell are crenulated. 



A species readily distinguished from the A, rugata. Sow., of the 

 London Clay by the general form, thinner shell, and less rugose sur- 

 face of the valves. 



Heme Bay. Collections of Messrs. Edwards and Bowerbank. 



Leda substriata, n. sp. Plate XVI. fig. 7. 



(Compare Nucula striata, Lam., Desh. Coq. Foss. t. 42. f. 4-6.) 



This shell, collected by Mr. Prestwich from the Thanet Sands at 

 Bichborough Castle and Pegwell Bay, is difficult to distinguish 

 from Nucula {Leda) striata, Lam., which it resembles in general 

 form, but is rather longer in a transverse direction, and the striae 

 diifer a little and are interrupted towards the posterior margin in 

 some of the specimens examined. 



Pecten Prestvichii, n. sp. Plate XVL fig. 8. 



Testa tenui, compressa, radiatim obsolete costata ; costis 30-36, subsquamosis ; 

 interstitiis oblique irregulariter striatis ; auriculis insequalibus, radiatis. 



Shell thin, compressed ; margin orbicular, with a rectangular beak ; 

 radiated with 30-36 very slightly raised ribs, distantly imbricated, 

 the intervening furrows twice as large as the ribs, irregularly and 

 obliquely striated ; ears unequal, with three or four radiated costse. 



Richborough Castle. Collected by Mr. Prestwich. 



ScALARiA BowERBANKii, u. sp. Plate XVI. fig. 9. 



Testa elongata, turrita, imperforata ; anfractibus 9-10, ventricosis, rotundatis, 

 suturis distinctis, longitudinaliter costatis ; costis 18-20, subacutis, interstitiis 

 transversim striatis ; anfracto ultimo carinifero ; apertura rotundata. 



An elongated, turreted, rather thick shell, with nine to ten ven- 

 tricose volutions, longitudinally costated ; costse eighteen to twenty, 

 somewhat acute, and slightly oblique, the ribs as well as intervening 

 furrows transversely striated ; the last volution carinated. 



The ribs on the lower volutions are sometimes divided and more 

 irregular than on the upper ones. 



This species is closely allied to, if not identical with, a shell ob- 

 tained by Sir C. Lyell from the Lower Tertiaries of Belgium {Sys- 

 teme Landenien of Dumont) . 



Heme Bay. Mr. Bowerbank' s Collection. 



Trophon subnodosum, n. sp. Plate XVI. fig. 10. 



Testa turrita, ovato-fusiformi, transversim temiissime striata, anfractibus convexis, 

 subcarinatis, superne angulatis, carina subnodosa; apertura ovata; columella 

 recurva ; canali breviusculo. 



Shell turreted, ovately fusiform, transversely striated, and faintly 

 decussated; volutions convex, upper part subangulated and nodulous ; 

 aperture ovate, with a short, open and recurved canal. 



Heme Bay. Mr. Bowerbank' s Collection. 



