ASTARTE. 103 



One has the shell preserved, the others are internal casts showing deep muscular 

 impressions. 



Tiipp.^. — Leymerie's specimens came from the Lower Xeocomian of Avalleur, 

 Chenay, and MaroUes (Aube). D'Orbigny records specimens from the Lower 

 Neocomian of St. Sauveur (Yonne). Pictet and Campiche figure specimens from 

 the Valanginian of Ste. Croix. 



Distribution. — Lower Greensand of Seend. 



AsTARTE suiiACUTA, (VOrbigiiij, 1850. Plate XIV, figs. 4 — G. 



1844. AsTARTE CARiNATA, A. (TOvhHjmj. Pal. Fran9. Terr. Crot., vol. iii, p. fi3, 



pi. cclxii, figs. 1-3. {noTiA.carwata, 

 Phillips, 1829.) 

 1847. — ACTTTA, tVOrhigny. Ibid., p. 759. (non A. acuta, Eeuss, 1846.) 



1850. — suBACUTA, d'Orhiyny. Prodr. de Pal., vol. ii, p. 77. 



1866. — — F. J. Pictet and G. Campiche. Foss. Terr. Crct. Sle. 



Croix (Mater. Pal. Suisse, ser. 4), 



p. 318. 

 1900 — — A. Wollemann. Die Biv. ii. Gastrop. d. deutsch. ii. 



hoUilnd. Neocoms (Abhandl. d. 



k. preussisch. geol. Land., N. F., 



pt. 31), p. 99. 



Description. — Shell triangular, much compressed, length greater than lieiglit, 

 slightly inequilateral. Antero-dorsal margin long and concave. Postero-dorsal 

 margin longer than the antero-dorsal, and either concave or nearly straight. Both 

 of these margins form obtuse angles with the well-rounded margin of tlie ventral 

 half of the shell. Umbones vei'y acute, projecting, often nearly median and not 

 curved. Lunule narrow, with a sharp edge. Escutcheon ver}^ narrow. 



Ornamentation consists of prominent concentric ribs separated l)y l)road inter- 

 spaces. The distance between the ribs increases in passing from the \uuho 

 ventrally. Margins of valves crenulated. 

 Measnreriicnts : 



(1) (2) 



Lenerth . 14 . 10 mm. 

 Height . 11 . 8 „ 



(1, 2) Pt'i-Hrt-bed. East Sbalford. 



Affinities. — A. snhacuta is distinguished from the other Cretaceous species by 

 its acute umbones and flattened valves. 



Ernvnis. — The only specimens which I have seen are in the ^Meyer Collection, 

 Sedgwick Museum. 



