ADDITIONS. 431 



the genus Tellina. Externally, as was pointed out by Stoliczka, it resembles 

 Lepton. 



Type. — From the Gault of Gdrodot (Aube). 



Distribution. — Gault of Folkestone. 



Cypeimeeia (Cycloeisma) stjbmeesa (Sowerby), 1836. Plate LXII, fig. 13. 



[For references see Vol. II, p. 192, foot-note.] 



Description. — Shell oval, inequilateral, convex, with the postero-dorsal part 

 flattened and limited by a rounded carina passing from the umbo to the postero- 

 ventral angle. Antero-dorsal margin nearly straight. Anterior margin rounded, 

 passing gradually into the moderately convex ventral margin. Posterior margin 

 truncated. Postero-dorsal margin slightly curved. Umbones of moderate size, 

 with a slight forward curvature. Lunule limited by a faint groove. Escutcheon 

 elongate, bordered by a carina. Ornamentation consists of small concentric ribs. 



Affinities. — The left valve, which is described above, was found by Mr. Jukes- 

 Browne in the Exeter Museum, and appears to be referable to Sowerby's Venus 

 submersa, the only apparent difference being in the greater length of the shell. 



The hinge agrees closely with that of C. (Cyclorisma) parva (Sowerby) (p. 185). 

 Externally the shell is similar to G. {Cyclorisma) rotomagensis (d'Orbigny), but is 

 less convex, more elongated, more inequilateral, with the forward curvature of 

 the umbones more marked and the posterior margin more distinctly truncated. 



Distribution. — Upper Greensand (zone of Schlcenbachia rostrata) of Blackdown. 



Genus — TAn<:s, Mcgerle von Muhlfeld, 1811. 



[Omitted from Vol. II, p. 194.] 



Sub-genus — Icanotia, F. Stoliczka, 1870. 

 (Palajont. Indiea, Cret. Fauna S. India, vol. iii, p. 145.) 



Tapes (Icanotia) sp. Plate LXII, fig. 14. 



Description. — Shell elongate-oval, very inequilateral, compressed, anterior and 

 posterior ends rounded. Ventral margin convex ; postero-dorsal margin nearly 

 straight. Umbones inconspicuous. Ornamentation consists of numerous, close, 

 radial ribs which are indistinct on the anterior part of the valve, and become 

 stronger and more widely separated on the posterior part, where a small rib may 

 occur between two larger ones. Length (approximate) 55 mm., height 26 mm. 



