CYPRTMERIA. 185 



Non 1840. Venus pauva, A. GoJdfiiss. Pctref. Germ., vol. ii, p. 246, pi. cli, fif;. 4 



(V. Goldfufisi, Qe'nntY., 1850; V. gtihparva, 

 d'Orbigny, 1850). 



— 1841. — — F. A. Itiimer. Die Verstein. d. nord-deutsch. Kreidefjeb., 



p. 72 (Venus snhinflexa, Kiiiner, 1836). 



— 1846. — — A. E. Reiii>s. Die Verstein. der bfihm. Kreideformat., pt. 2, 



p. 20, pi. .xli, figs. 16, 17. 



— 1863. — — A. V. Sfromheck. Zeitschr. <ler deutsch. gfol. GesclLsch., 



vol. XV, p. 146. 



— 1868. — — A. Briaii and F. L. Cornet. Meule de Bracquegnies (Mem. 



cour. et Me'in. des Sav. I'trangcrs, 

 vol. xxxiv), p. 75, pi. viii, figs. 1, 2. 



— 1877. Cytherea PARVA, G. l?o/i»!. Zeitschr. der deutsch. geol.Gesellsch., vol. xxix, 



p. 241. 



— 1883. Vencs cf. PARVA, A. Fritsch. Stud, im Gobicte der biihm. Kruidefurniat., iii, 



Iserschicht., p. 109, fig. 77. 



— 1885. Venus parva, F. JViifliiui. Die Fauna d. baltisch. Cenoman. (PaliEont. 



Abhandi., vol. ii), p. 32, pi. v, fig. 11. 



— 18fl3, — — Fritsrii. Op. rit., V, Priesen. Sehicht., p. 98, fig. 118. 



Descriptidji. — Shell small, nval, convex, inoileratcly inequilateral. Antero- 

 (lorsal margin slightly concave, or nearly straight, forming a rounded angle with 

 the anterior margin which curves rapidly to join the convex ventral margin. 

 Posterior margin rounded or .subtruncate. Postero-dorsal margin slightly convex. 

 Umbones rather prominent, curved inwards and forwards. liunule broad, ovate, 

 more or less projecting, limited l)y a groove. Pal Hal sinus large, angular. 

 Ornamentation consists of small, somewhat irregular, coucenti'ic ribs, and occasional 

 growth-rings. 



Hinge: In the rio-ht valve the antei'ior and median cardinals are stout and 

 nearly parallel, and the two posterior teeth (wdiich represent the posterior cardinal) 

 are oblique and diverging ; in front of the anterior cardinal is a groove, bounded 

 by a ridge above and l)elow, parallel to the inner margin of the hinge-plate. In 

 the left valve the antei-ior and median cardinal teeth diverge widely under the 

 umbo and the posterior cardinal is oblique; the anterior cardinal is continued 

 forward into a i-idge along the inner margin of the hinge-plate. 



Measurements : 



(1) (2) (3) (4) (5) 



Length . 20-5 . 21 . 20 . 20 . Ii) 

 Height . 17 . 17-5. 17-5. 17 . 1<^> 



(1) P,-rno.-hca, East Sliair..rd, 

 (2—8) Crackers, Atherfield. 

 Affinities. — The differences between this species and ('. {Ct/dorimin) rofimiKjeiisin 

 are given below. 



The foiin fiom IJiacquegnies, which was referred to Vitnix jitirrn by Hnart and 

 Cornet, is less elongate. 



