294 Systematic Paleontology 



Pholidops ovata Hall 

 Plate LIII, Figs. 10-12 



Pholidops ovatus Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 490, pi. ciiib, 



fig. 7. 

 Pholidops ovatus Weller, 1903, Geol. Surv. N. J., Pal., vol. iii, p. 226, pi. xx, 



figs. 27-29, p. 300. 



Description. — " Shell ovate : apex excentric. Surface marked by fine 

 concentric lamelljE of growth, which are wider on the posterior part of 

 the shell. Very minute radiating striae are sometimes visible." Hall, 



is.yj. 



The valves in thi.s species are nearly flat and the ventral valve outside 

 of the scar of attachment has from o to 8 concentric lamellae. The 

 cementation scar is quite large, is easily recognized in being devoid of 

 lamellae, and is usually fiat, but may be slightly concave. This is an 

 abundant species in the Bryozoa beds near the base of the Iveyser. 



Diameter 10 to 15 mm. 



Occurrence. — Helderbekg Formation, Keyser MEiiBER. Keyser, 

 West Virginia ; Tonoloway, Maryland. 



Collection. — IT. S. National Museum. 



Pholidops tumida n. sp. 

 Plate LIII, Fig. 17 



Description. — Shell above the average in size for the genus, elongate- 

 oval in outline, with the posterior end somewhat truncated. Valves quite 

 convex, with the highest point near the posterior end ; beaks nearly mar- 

 ginal and abruptly elevated above the posterior margin; lamellfB dis- 

 tinctly imbricating, from fifteen to eighteen on each valve. A^entral 

 cementation scar small, but readily discernible. 



This species differs from P. multilamellosa in its elongate oval shape, 

 tumid valves, and the nearly marginal beaks ; from other Lower Devonian 

 species in the greater number of lamellae and the nearly marginal beaks. 



Length about 14 mm. 



Occurrence. — Oriskaxy Formation, Shriver Member. Winchester 

 Road, near Cumberland. 



Collection. — Marvland Geological Survey. 



