Maryland Geological Sukvey 293 



Lower Oriskany of New Jersey, aud has recently been redescribed and re- 

 figured by Weller." 



Occurrence. — Helderbeeg Formation, New Scotland Member. 

 Devil's Backbone, uppermost beds. 



Collection. — Georp;e M. Boeder. 



Superfamily CRANIACEA 

 Family CKANUUAH 



Genus PHOLIDOPS HalP 



Pholidops multilamellosa n. sp. 

 Plate LIII, Figs. 8, 9 



Description. — Shell large, broadly and regularly oval in outline or 

 slightly shouldered posteriorly. Valves depressed convex; dorsal beak 

 acute, small, and situated just a little back of the center, with about 

 fifteen lamellae of growth ; ventral scar of attachment fairly large, smooth, 

 and flat, outside of which are about ten well-developed lamellae. The 

 length of the largest specimen is 8 mm., and 6 mm. in width. 



This species differs from associated Oriskany Pholidops in its large 

 size, combined with the subcentral beaks and the great number of lamellae. 



Length about 1.2 cm., width about 1 cm. 



Occurrence. — Oriskany Formation, Shriver Member. Cash Valley, 

 21st Bridge. 



Collection. — U. S. National Museum. 



^ Geol. Survey N. J., PaL, voL iii, 1903, p. 323, pi. xli, fig. 4. 



'For a good generic definition, see Hall and Clarke, 1892, Nat. Hist. N. Y., 

 Pal., vol. viii, pt. i, p. 155. The writer no longer has any doubt in regard to the 

 fact that Pholidops was cemented to foreign objects by a small part of the 

 ventral beak. The cicatrix has been seen in P. ovata, P. multilamellosa, P. 

 tumida, and P. implicata, the last being from Gotland. In all these cases the 

 scar is flat or concave and devoid of lamellte, and in the same species the 

 lamellae continue in the dorsal valve quite close to the protegulum. 



