136 CRETACEOUS LAMELLIBRANCHIA. 



but is much larger and stouter, and the lunular region is more deeply excavated ; 

 also the umbones appear to have a greater anterior curvature. 



Type. — From Benniworth Haven, in the Sedgwick Museum. 



Distribution. — Claxby Ironstone (zone of Belcmnites lateralis) of Benniworth 

 Haven and Donnington. 



Cypeina tealbiensis, sp. nov. Plate XX, fig. 13 a, l. 



Description. — Shell very thick, large, elongate, oval, regularly convex, very 

 inequilateral. Antero-dorsal margin concave. Anterior margin rounded, curving 

 rapidly, passing gradually into the ventral margin. Posterior margin rounded, 

 forming an obtuse angle with the long, slightly convex postero-dorsal margin. 

 Umbones broad, anterior, curved inward. A faint carina extends from the umbo 

 to the posterior end. Lunular region deep. Escutcheon large, deep, limited by a 

 strong carina. Ornamentation consists of growth-ridges. 



Measurements : 









(i) 



(2) 



Length . 



105 



62 mm 



Height . 



82 



(1, 2) Tealby Limestone. 



49 „ 



Affinities. — In its elongate form, and deep, carinate escutcheon this species 

 resembles C. boloniensis, de Loriol, 1 from the Portlandian. 



Remarks. — There are two specimens in the Sedgwick Museum and one in the 

 British Museum. The hinge has not been seen. 



Distribution. — Tealby Limestone of Walesby and Claxby, Lincolnshire. 



Cypeina, sp. Plate XXI, fig. 3. 



A large Cyjjrina from the Tealby Limestone of Claxby is known by a right 

 and a left valve, now in the Sedgwick Museum, and appears to belong to a distinct 

 species. It shows some resemblance to G. aixjulata, Sowerby (see page 141), but 

 differs from that species in the greater ventral slope of the postero-dorsal margin ; 

 the greater obliquity of the posterior margin ; the smaller curvature of the 

 umbones ; the longer and less concave antero-dorsal margin ; and in the absence 

 of a carina cutting off a postero-dorsal area. The surface of the shell is 

 imperfectly preserved, but in places there is evidence of w r ell-marked growth- 

 ridges. Length, 92 mm. Height, 80 mm. 



1 De Loriol and Pellat, ' Portlandien de Boulogne-sur-Mer ' (lbb'b'), p. 54, pi. v, fig. 9. 



