404 Systematic Paleontology 



area is relatively lower and always more incurved than in S. vanuxemi and 

 its variety. The finer surface detail in all of these forms is spinose. 



It is probable that Weller ' had before him Coeymans examples of this 

 species, for he states : " A few small specimens, which are apparently the 

 young of this species [S. cyclopterus] agree closely with specimens of S. 



vanuxemi from the Manlius limestone, and at first were so identified 



It is possible that S. vanuxemi is ancestral to this Helderbergian species." 



This variety occurs locally in abundance in the upper part of the Keyser 

 member. 



Length 8 mm. ; width 10 mm. 



Occurrence. — Helderberg Formation, Keyser Member. Winchester 

 Eoad at Pinto in a shaly limestone, cut of Baltimore and Ohio Kailroad 

 I mile southwest of Eawlings, Tonoloway. 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Spirieer eriensis Grabau 



Plate LXIX, Pig. 7 



Spirifer eriensis Grabau, 1900, Bull. Geol. Soc. Amer., vol. xi, pp. 366-367, pi. 

 xxi, figs. 2a-&. 



Description. — " Shell small, pedicle valve strongly convex, almost 

 ventricose, subrhomboidal in outline, with the beak much elevated and 

 gently incurved. Mesial sinus pronounced ; angular in the center, with the 

 sides nearly flat, gradually and uniformly increasing in width from the 

 beak forward. Sometimes it is slightly rounded in the bottom. It is pro- 

 longed at the front of the shell as a prominent rounded lip. On either side 

 of the sinus is a moderately strong, broadly rounded, but not very promi- 

 nent plication, in addition to which there are about three or four on either 

 side, which are fainter and progressively become narrower away from the 

 sinus. Interspaces narrow, having the form of a depressed line, the broad- 

 est next to the plication adjoining the sinus. Brachial valve almost semi- 

 circular, moderately convex, with a straight hinge-line, which is shorter 

 than the greatest width of the valve. Beak elevated above the hinge-line 



'Geol. Surv. N. J., Pal., vol. iii, 1903, p. 287. 



