PROF. E. FORBES ON LOWER GREENSAND FOSSILS. 241 



are distant, and on a perfect specimen half an inch in breadth, are- 

 ten in number. The furrows between them are traversed by nu- 

 merous regular raised radiating ribs, so as to give the shell a fenes- 

 trated aspect. 



Log. Peasemarsh. 



Note. Allied to the Astarte ( Venus ?) multistriata of Blackdown. The 

 strong radiating striae and the almost lateral position of the beak, are excellent 

 distinguishing characters. 



28. Venus ? [striato-costata~\. 



V. ? testa oblonga, triangulari, inaequilaterali, plus minusve 

 depressa, costis elevatis, reflexis, distantibus, concentricis ornata, 

 interspatiis transverse striatis, interstitiis striarum longitudi- 

 naliter minutissme striatis, lunula excavata. 



Lon. 0-^z ; lat. 0^ unc. 



Shell more or less rounded, triangular or oblong, sometimes 

 much depressed, sometimes almost inflated, regularly ribbed trans- 

 versely, ribs usually 7 — 9 ; the ribs are acute and reflexed, the 

 interspaces regularly furrowed transversely, and finely striated 

 longitudinally. The anterior extremity is usually produced and 

 truncated, the posterior very short. In general aspect it comes 

 near Astarte {Venus ?) formosa of the Blackdown beds, but differs 

 in form, convexity, and number of ribs, the more prominent of 

 which are more numerous and closer set in the Blackdown species. 



Note. This shell and the last appear to me to be more nearly allied to 

 certain species of Venus (as Venus fasciata of Montagu) than to any known 

 Astartes. Specimens of this species were sent to M. d'Orbigny, who identified 

 them with his Astarte numistnalis. If so, his figure and description of that shell 

 do not notice the peculiar characters of the interspaces of the ribs. It resembles 

 much more nearly his A. striato-costata, and is probably identical with that 

 species. I have accordingly retained that specific name provisionally, in pre- 

 ference to running the risk of creating a useless synonym. 



There are casts of apparently several other species of Venus in the Society's 

 collection, but too imperfect to determine. 



29. Crassatella Robinaldina D'Orb. T. C. pi. 264. p. 10—13. 



Specimens of this remarkable shell, easily distinguished by 

 the angulated diverging ribs of its surface *, are in the col- 

 lections of Mrs. Smith of Tunbridge Wells (from Maidstone) 

 and of Mr. Hills of Chichester (from Court-on- street). Iden- 

 tified by comparison with French specimens. 



30. Astarte obovata Sow. M. C. t. 353. 



Var. a. Margin crenulated. Astarte transversa Leym. pi. 

 5. f. 5. ? Certainly Astarte transversa of D'Orbigny, T. C. pi. 

 261. 



Loc. Hythe. 



* We have a similar style of ribbing in the recent Crassatella Tellinoides, a 

 species inhabiting the coasts of Massachusetts 



R 



