66 BULLETIN OF THE LABORATORIES 



Genus Prothyris, Meek. 



Prothyris meeki, Wmchell. 



This species occurs frequently in the shale below congl. II, but 

 is by no means limited to that horizon. Its range and legitimate lim- 

 its of variation have not been fully studied. 



Sangainolites iGoniophora) senilis, sp- "• 

 (Plate IX, Fig. 28.) 



Cf. Sanguinolites cuncatus, DeKoninck, and Goniophora siibi'ecta. 

 Hall. 



Shell of rather large size, nearly rectangular, hinge and ventral 

 margins nearly parallel, nearly straight and of nearly equal length. . 

 The anterior dorsal margin is nearly straight, making with the hinge 

 an angle of about 120° or less, somewhat produced; posterior margin 

 truncate at about a right angle and again obliquely truncate at the up- 

 per third (sometimes apparently curved rather than doubly truncate ; 

 in most specimens the postero inferior angle is more acute and pro- 

 duced than in the one figured, thus approaching G. subrecta, H.) 

 Surface quite convex along the very prominent and rather acute post- 

 umbonal ridge, the greatest convexity being half way from the beak 

 to the postero-veniral angle. On either side of the ridge the surface 

 is plane for some distance, but anteriorly becomes concave, forming a 

 broad sulcus passing from the middle of the ventral margin toward the 

 beak; j)osteriorly the surface is flat for a considerable distance from 

 the upper angle. The umbo is rather prominent, 'i'he surface is or- 

 namented with very prominent, raiher irregular, close, concentric 

 lines, which are acutely angled upon the umbonal ridge. Length 60 

 mm: height 25 mm; beak distant from the anterior about 11 mm. 

 Found only in shales four feet below conglomerate I, near Granville, 

 O. In some specimens the resemblance to S. cuneatus, Dekon., ap- 

 proaches identity. From Goniophora subrecta it differs chiefly in the 

 less elevated anterior extremity and slightly less produced infero-pos- 

 terior angle. The relation is so obvious that we regard this shell as 

 increasing the Devonian character of our division I. 



