3b NEW YORK STATE UrCSElTM 



BRACHIOPODS 



Oriskania sinuata, sp. nov. 



Plate 5, fig. 9-13 



1892. CentroneUa sp. nov., Clarke, op. cit. p. 414 



Shell of comparatively large size, elongate ovate in outline. Lateral 

 commissure sigmoid. Pedicle-valve convex, strongly ridged medially, with 

 sharply sloping sides. Beak prominent, arched and so incurved as largely 

 to conceal the deltidial plates. Brachial valve flat in the umbonal 

 region. A low median sinus begins at about the center of the valve, 

 becomes wider and deeper over the pallial region and makes a strong 

 linguate depression on the anterior margin. On the interior the brachial 

 valve bears the strong cardinal plate and process peculiar to this genus, 

 and shows deep addiictor impressions and pronounced vascular sinuses 

 over the pallial region. 



This shell, which sometimes attains the proportions of Oriskania 

 navicella Hall and Clarke of the Oriskany sandstone at Rondout 

 and Knox, differs from that species in its deeply sinuate brachial valve. 



Cryptonella (?) fausta, sp. nov. 



Plate 6, flg. 1-8 



1892. Cryptmiella, sp. nov., Clarke, op. cit. p. 414 



Shell of medium size, elongate oval, commissure nonsinuate. Valves 

 inequiconvex or subequiconvex. Beak of pedicle-valve generally erect 

 and prominent, with well developed cardinal slopes, sometimes arched, 

 partially concealing the deltidial plates. Surface of the pedicle-valve 

 convex, sometimes with a broad median prominence which adds to the 

 convexity; sides gradually sloping; anterior margin nonsinuate. Brachial 

 valve somewhat less convex, slightly depressed in the pallial region; 

 in some specimens ridged medially in the umbonal region. 



Interior of the pedicle-valve with muscular scars, obscure vascular 

 sinuses and dental plates developed into a short spondylium. 



Surface generally smooth ; sometimes with traces of obscure plica, 

 tions about the margins. 



The shells included under this name may with more material be found to 

 embrace two distinct forms, those having nearly equiconvex valves and those 

 in which the pedicle-valve is the deeper and distinctly ridged medially. The 



