218 CKETACEOUS LAMELLIBRANCHIA. 



Tijpe. — From Atlierfiekl, in the Mu«euin of the Geological Society. 

 Distribution. — Lower Greensaud (Crackers) of Atlierfiekl. Atherfiekl Beds of 

 East Shalford and Sevenoaks. Sandgate Beds of Parham Park. 



Genus — Solecuhti's, //. M. J), df llhn'nrilk', 1824. 



('Diet. Sc'i. luit.,' viil. x-xxii, p. 3-51.) 



Stih-f/enus — Azoii, 11^. E. Latch, 1847. 



(In Gray, ' Ann. Mag. Nat. Hist.,' vol. xx, p. '272 ; and ' Proc. Zool. Soc.,' 1847, p. 189.) 



SoLECDRTUS (AzoK r) PEi,.\Gr, iVOrhii/in/, 1 8")0. Plate XXXV, fig. 4. 



1850. SoLECURTUs Pelagi, a. d'Orhiijnij. Prodr. de Pal., vol. ii, p. 1.58. 



1867. — — E. Gurromjer. Album Pak'ont. de la Sarthe, p. 12, 



pi. XV, fig. 6. 

 1870. — — F. StoJiczha. Palseont. Indica, Cret. Fauna S. India, 



vol. iii, p. 99. 



Descrij)tion. — Shell elongate, considerably inequilateral, moderately convex, but 

 slightly concave at the middle of the sides. Postero-dorsal area flattened or slightly 

 concave, limited by an indistinct carina. Antero-dorsal margin cui-ved ; anterior 

 margin rounded; postero-dorsal margin straight, nearly j^arallel to the ventral 

 margin; posterior margin curved, slightly oblique. Ornamentation consists of 

 small concentric ribs near the umbo, and of growth-rings elsewhere. Length :?0 

 mm. ; height 12 mm. 



Ajjiuities. — The identification of the English specimens with tl'Orbigny's species 

 is not quite free from doubt, since only two valves, both somewhat imperfect, have 

 yet been seen. In the specimen figured by Gueranger the postei'o-dorsal area 

 seems relatively higher than in our si)eciiHens ; also the postero-dorsal margin is 

 less nearly straight, but this difference may be due to imperfect preservation. 



S. Pelagi seems to be closely allied to S. Guc.ra>if/erl, d'Orbigny,' but the 

 carina is less distinct, and the postero-ventral angle appears to be more rounded. 



Until specimens showing the hinge satisfactorily have been found, the generic 

 position of this species must be regarded as doubtful. 



Ti/pe. — From the Cenomanian of Le Mans. 



Distribution. — L^pper Greensand (zone of SclihrnlKicJiin ruatrdtn) of Blackdown. 



^ 'Pal. Frany. Terr. Crt't.,' vol. iii (1845), p. 321, pi. cccli, figs. 1, 2. Gut'ranger, 'AUnun 

 Pak'ont. de la Sarthe' (1867), p. 12, pi. xv, fig. 4. An inturual cast of a left valve from the Upper 

 Gi'eensaud of Warminster resembles S. Guerangeri. 



