164 CEETACEOITS LAMELLIBRATsTHIA. 



Two internal casts from tlio C'amljridge Greensancl (derived from the Gault) 

 were identified l)y Mr. Jukes-Browne as Cnrhis f/duUina, Pictet and Roux. Tlie 

 specimens are in the Sedgwick Museum, and no other examples appear to have 

 been Connd. The t.yp(> of ('. (/inilfiiia came from the Gault of Saxonot. In 

 external I'nrm tliis species agrees closely with VmranVvim, hiif llic liiiige is 

 unknown, so (lint the generic position cannot be determined with certainty. 



Unicakptum iMNriMEKiRNSE {MunlcII), 1822. Plate XXV, figs. 13, 14. 



1822. Venus? rinomekiensis, G. Mantell. Foss. S. Downs, p. 126. pl.xxv, fig. 5. 

 18.50. Panop;ea — A. cVOrhujny. Prodr. do Pal., vol. ii, p. 1-57. 



IS.'J-t. Unicardium rinOtMERIENSE, J. Morris. Cat. Brit. Foss., cd. 2, p. 229. 

 1865. Cardium — F.J. rirti'l find G.Campiehe. Foss. Terr. Cn't. 



Ste. Croi.v (Mater. Pal. Suisse, 

 sor. 4), p. 195. 

 Nou 1^50. Arca ringmerensis, II. B. Gcinitz. Das Quadorsandst. oder Kreidegeb. in 



Dentscliland, p. 162. 



— 1872. MuTiELi.A RiNOMERENRis. Tf. B. Gcinlt-.. Das Elbthalgeb. in Saclison (Pal- 



oeoutographica, vol. xx, pt. 2), 

 p. 61, pi. xvi, figs. 11-13. 



— 1877. — — A. FrUfrh. Stud, im Gebiotc der bolini. Kroido- 



format. II Woisseuberg. w. Maluitz. 

 Schicht., p. 115, fig. 75. 



— 1883. — — FriUcli. Ibid. Ill Iserschicht., p. 100, fig. 64. 



— 1889. — — Fritsch. Ibid. lY Teplitz. Schicht., p. 78. 



— 1807. — — Friiscli. Ibid. VI Chlomek. Schicht., p. 54, fig. 59. 



Descnj^tion. — Shell subquadrate, rounded, inflated, antero-dorsal part com- 

 pressed, length rather greater thaji height, inequilateral, anterior j^art larger than 

 the posterior part. Antero-dorsal margin nearly straight. Anterior margin 

 moderately convex, making an obtuse angle with the antero-dorsal margin and 

 curving rapidly near the ventral margin. The latter is moderately convex and 

 curves upward to join the posterior margin, which is slightly cuiwed, and forms 

 an obtuse angle witli the postero-dorsal margin. Umboncs large, ])roinin('Tit, 

 contiguous, ciu'ving forward. Ornamentation consists of strong, narrow, con- 

 centric ridfjes. 



