398 Systematic Paleontology 



Occurrence. — Helderberg Formation, New Scotland i\lE:MBER. 

 Corriganville, Devil's Backbone, Maryland; Keyser, Cherry Eun, West 

 Virginia. 



Collections. — U. S. National Mnsenm, American Museum of Natural 

 History. 



Spirifer cumberlandi.e Hall 

 Plate LXVIII, Figs. 9-lG 



Spirifer cumherlandiw Hall, 1857, Tenth Ann. Rept. N. Y. State Cab. Nat. 



Hist., p. 63. 

 Bpirifer submucronatus Hall, 1857, Tenth Ann. Rept. N. Y. State Cab. Nat. 



Hist, p. 62. 

 Spirifer submucronatus Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 419, pi. 



xcvi, figs. 7a-/. 

 Spirifer cumberlandiw Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 421, pi. 



xcvi, figs. 9a-9fl'. 

 Spirifera cumberlandiw Hall, 1883, Second Ann. Rept. N. Y. State Geol., p. 



58, figs. 16-23. 

 Spirifera submucronata Hall, 1883, Second Ann. Rept. N. Y. State Geol., 



pi. Iviii, figs. 5-7. 

 Spirifer cumberlandiw Hall and Clarke, 1893, Nat. Hist. N. Y., Pal., vol. viii, 



pt. ii, pp. 17, 36, pi. xxxiii, figs. 16-23. 

 Spirifer submucronatus Hall and Clarke, 1893, ibidem, vol. viii, pt. ii, pp. 



17, 36, pi. xxxiii, figs. 5-7. 



Description. — " Shell broadly semicircular ; valves moderately and 

 nearly equally convex : ventral valve regularly convex ; mesial sinus nar- 

 row, shallow, and flat in the middle ; beak gently incurved, and projecting 

 slightly beyond the hinge-line : dorsal valve having a narrow flattened 

 mesial fold, M'ith a faint depression down the center; beak scarcely in- 

 curved, and nearly in the same plane with the cardinal margin ; hinge-line 

 straight; extremities extended; area broad, nearly flat, parallel with the 

 axis of the shell ; foramen somewhat large, often partially or entirely closed 

 [by deltidial plates]. Surface marked by from fourteen to seventeen 

 simple rounded costse, which are crossed by concentric elevated lines or 

 lamellae." Hall, 1857. 



The lamellae are again crossed by very delicate radiating striae, but these 

 do not terminate in minute spines as in S. trihulis and S. intermedins. 



This species most resembles S. intermedins, but differs in having de- 

 and more numerous plications and relatively higher and more 



