68 BULLETIN OF THE LABORATORIES 



been seen, but there is at least a close resemblance to Winchell's spe- 

 cies as gathered from the description. 



Shell small, compressed, elongate elliptical, with nearly parallel 

 margins and sub-terminal beaks. Rather more than twice as long as 

 high, height nearly the same anteriorly as posteriorly. Hinge-line 

 two- thirds the entire length, often diverging posteriorly, sometimes 

 shorter ; postero-dorsal margin very obliquely truncate, curving more 

 rapidly near the middle of the height and passing by a rapid curve into 

 the nearly straight ventral margin. Anterior margin rather distinctly 

 concave above the middle, strongly convex bejow. Beaks minute, 

 not projecting, near the front; posterior-umbonal slope gentle, no well- 

 defined ridge; shell thin, surface marked by fine lines of growth. 

 Length 13 mm, height 5.2 mm ; hinge-line 8 mm ; beak 2 mm. from 

 anterior. Shale 4 feet below Congl. I, at the " Dug-way," Granville, 

 Ohio. No. 1372. 



Sangioijiolites (SpJie/iotios) traits versus, Dekoninck. 



Sanguinolites (Cypricardia?) rigida. W. and W. 



(Plate IX, Fig. 22.) 



*' Shell elongate, quadrangular, a little widest at the posterior end. 

 Dorsal line straight, bounded by a rather broad escutcheon, which 

 is more than half as long as the entire length of the shell. Anterior 

 end truncate, prolonged near the basal margin ; posterior extremity 

 oblicpiely truncate; basal line straight, slightly emarginate, a little an- 

 terior to the middle, by a shallow sinus which crosses the shell from 

 beak to base. Lunule large, deeply marked; beaks small, flattened 

 on the umbones, and enrolled, situated anteriorly ; umbonal ridge 

 very prominent and angular, extending from the beak to the posterior- 

 basal angle. A second, but less prominent ridge passes about mid- 

 way between the first and dorsal line. Surface marked by sharp, 

 closely-arranged lines, {)arallel to the margin, which are bent at right 

 angles as they cross the umbonal ridge, and less abruptly at the minor 

 ridge. Interior of shell with a sharp muscular ridge passing from the 

 anterior side of the beaks, with a forward curvature, about ^3 distance 

 across the shell. Hinge-teeth absent, probably partially external lig- 

 ament," 



