OF DENISON UNIVERSITY. 67 



SanguinoJites inarsliaUensis, ^^i"- ? 

 (Plate V, Fig. ii ; Plate VII, Fig. lo.) 



This shell bears some resemblance to S. transversus, Dk. (=: Cypri- 

 cardia rigida), but differs in the posterior margin. vShell sub-quadrate 

 or sub-ellipsoidal, transversely elongate, with greatest convexity above 

 the middle; hinge nearly straight and somewhat shorter than the shell, 

 at its posterior termination being the greatest height of the shell ; ven- 

 tral margin shorter, • somewhat concave or nearly straight, rapidly 

 curving anteriorly to a point above the middle of the height, where it 

 intersects the short, concave antero-dorsal margin ; posterior margin 

 doubly truncate, first below for two-thirds the height by a line inclined 

 with the ventral about 130°, above by a shorter line making nearly the 

 same angle with the cardinal line, giving the shell a nasute appearance 

 behind. A prominent ridge passes from this projection toward the 

 beaks and a similar one from the lower posterior anglc% between which 

 a decided sulcus is frequently observed, especially in large specimens. 

 A less distinct sulcus extends from the middle of the lower margin to- 

 wards the somewhat flattened, incurved beaks. 



The following measurements illustrate the proportions : Length 

 22 mm, height 11 mm, convexity of single valve 3-4 mm; L. t^t, mm, 

 H. 15 mm; L. 28 mm, H. 14; L. 24 mm, H. 12.5 mm; L. 40 mm; 

 H. 18 mm. 



The identification as above was made at the suggestion of Prof. 

 Winchell, as we were unable to harmonize the description with our 

 specimens. This may be accounted for by the fact that the descrip- 

 tion was drawn from rather young forms, while ours have the peculi- 

 arities strongly marked. 



Free-stone of middle Waverly. Ciranville, O. 



San£uinolites uiiiomforniis, ^^''». 

 (Plate IX, Figs. 5, 7-9.) 



Quite a number of very small shells, with rather constant charac- 

 ters from the basis of this description. The interior has in no case 



