Marylaxd Gkoi-ogical Sukvky 207 



Surface usually smooth or very finely papillose, hut in its perfect condi- 

 tion covered by numerous fine seta. 



The Maryland specimens are rather poorly preserved internal impres- 

 sions which occur infrequently. They show distinctly a shallow furrow 

 which extends from the vicinity of the beak to the front of the ventral 

 valve, produced by the internal medium septum. This species is dis- 

 tinguished by its small size, nearly circular outline, subequally convex 

 valves, generally smooth surface, and median furrow of internal impres- 

 sions, especially of ventral valve. 



Concerning the specimens found in the Onondaga, Kindle states : 



This species is represented by numerous ventral valves but the dorsal valve 

 has not been observed. Nearly all of the specimens represent casts of the 

 interior but one silicifled specimen shows the base of the fine setae over the 

 anterior third of the shell and a highly papillose surface over the remainder 

 of the shell. The outline of the muscular scars is not very clearly shown in 

 the specimens. Two narrow ridges on either side of the septum appear to 

 represent them in the casts. 



Length, 10 mm.; width, 11 mm. 



Occurrence. — Romney Formation, Onondaga Mejiber. Williams 

 Road, 3\(, miles southeast of Cumberland; Tonoloway. Hamilton Mem- 

 ber. Ernstville. 



Collections. — Maryland Geological Survey ; Xew York State Museum ; 

 AmericBB Museum of Natural History. 



Genus ANOPLOTHECA Sandberger 



Subgenus COELOSPIRA Hall 



Anoplotheca (Coelospira) acutiplicata (Conrad) 



Plate XX, Figs. 16-23 



Atrypa acutiplicata Conrad, 1841, Fifth Ann. Rep. N. Y. Geo!. Survey, p. 54. 

 Atrypa acutipUcata Hall, 1862, Fifteenth Rep. N. Y. State Cab. Nat. Hist., 



1862, pi. xi, fig. 17. 

 Leptocoelia acutiplicata Hall, 1867. Pal. N. Y., vol. iv, p. 365, pi. Ivii, figs. 30-39. 

 Anoplotheca (Coelospira) acutiplicata Hall and Clarke, 1893, Pal. N. Y., vol. 



viii, pt. ii, p. 136, pi. liii. figs. 32-39. 

 Anoplotheca acutiplicata Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 



144. 



