CYPRICARDINIA. 91 



G. im.jpressa^ Paclat, appears to agree iu form and ribbing, but is of a much 

 larger size. 



2. OYPEiCAEmNiA ? sp. Plate IX, fig. 22. 



Description. — Shell small, oblique, transverse. Anterior side much contracted, 

 possibly subangular. Antero-iuferior margin rather long, oblique. Inferior 

 margin moderately short, very slightly convex. Postero-inferior corner rounded, 

 very convex. Hinge-margin about three-quarters (?) of the length. Umbo 

 broad, flat, prominent, curving forward, and situate anteriorly. Contour of back 

 flattened horizontally between lines of curvature which run from the umbo to the 

 lower part of the sides. Surface covered by about twenty large, broad, low, sub- 

 angular, concentric ridges, apparently marked with minute crenulations. 



Size. — 13 mm. long, 9 mm. wide. 



Localities. — A specimen from Sloly is in the Barnstaple Atheneeum. 



BemarJcs. — This specimen is very obscure. It has every apjDcarance of 

 belonging to the genus Cypricardlnia, though there seems no positive evidence 

 that it does so. 



3. Ci'PRICARDINIA, sp. 



Description. — Shell minute, suborbicular, very convex, oblique. Umbo elevated, 

 prominent, incurved, direct, anterior. Anterior margin narrow, apparently 

 nearly straight. Inferior margin oblique, slightly convex. Postero-inferior 

 corner subangular, produced. Posterior margin long, oblique, slightly convex. 

 (Hinge-margin unseen, perhaps half the length of shell.) Lunule apparently deep 

 and undefined. Contour very convex, divided by a blunt angle from umbo to 

 postero-inferior corner, behind which it is flatter and steeper. Surface covered 

 with numerous strong parallel ridges on the back. 



Size. — About 2 mm. long, 1*5 mm. high, and '5 deep. 



Locality. — A single specimen from Marwood is in the Barnstaple Athenaeum. 



BemarJcs. — This tiny shell seemed too indistinct for figuring, but by a minute 

 examination many of its details have become evident. It reminds one strongly of 

 the general form of Opis, but no doubt is really a species of Cypricardlnia. 



Affinities. — It differs from C. scalaris by its shortness, convexity, and much 

 finer striation, in the last point coming nearer the species last described. 



