340 PALEONTOLOGY OF NEW YORK 



DESCRIPTIONS OF NEW SPECIES FIGURED IN THIS VOLUME. 



Orthis I Saffordi, sp. nov. 



PLATK V A, FIGS. 38-40. 



Shell semielliptical in outline ; valves subequally convex, the pedicle-valve 

 being the more elevated at the apex. Hinge-line long and straight, giving 

 the shell a strophomenoid appearance. Cardinal area low ; delthyrium un- 

 covered. 



Surface covered with numerous rounded, sharply elevated striae, increas- 

 ing by intercalation, and crossed by exceedingly fine concentric lines. 

 The details of the interior are not known, but the relations of the shell to 

 Orthis are demonstrated by the open delthyrium and simple cardinal pro- 

 cess, slightly lobate on its posterior face. 



Length of the type specimen, 17 mm. ; width along the hinge, 22 mm. 



Trenton horizon. East Tennessee. 



Orthis ? Holstoni, Safford. 



I'LATE V A, FIUS. 30-37. 



Shell transverse ; outline semicircular. Hinge-line long and straight. Pedi- 

 cle-valve with a high, vertical, cardinal area, transected by a very broad, 

 uncovered delthyrium ; beak not incurved ; surface sloping evenly toward 

 the margins, slightly rounded in the median line, and faintly depressed 

 toward the cardinal angles. Brachial valve depressed convex, nearly flat, 

 with a broad and low median sinus. 



Surface of both valves covered with fine, elevated, radiating striae, crossed 

 by faint, concentric, cancellating lines which have a slight retral bend on 

 the striae. 



This shell has very much the aspect of a Clitambonites, but of the two 

 specimens examined, neither has evidence of a deltidium, and a trans- 



