Maryland Geological Survey 211 



the Geological Museum of the Ohio State University. This species is 

 distinguished by its shape, size, small number of rounded plications, fold 

 on ventral with sinus on dorsal valve, and pustulose surface. 



Length, 9 nun- ; width, 12 mm. 



Occurrence. — Romney Formation, Hamilton Member. East bank 

 Evitts Creek below Wolfe Mill; Williams Road, 3^ miles southeast of 

 Cumberland ( ?) ; on Qldtown Road east of Maryland Ave., Cumberland; 

 on National Road northeast of Cumberland; on road about half way be- 

 tween Romney and Hanging Rock, W. Va. ; on Romney-Hanging Rock 

 Road about \ mile north of Romney, W. Va. 



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

 American Museum of Natural History. 



Genus ATHYRIS McCoy 



Athyris sriRiFEROiDES (Eaton) 



Plate XXI, Figs. 1, 2 



Terebratula spiriferoides Eaton, 1831, Am. Jour. Sci., vol. xxi, p. 137. 

 Atrypa concentrica Conrad, 1838, An. Rep. Geol. Surv. N. Y., p. 111. 

 Atrypa concentrica Hall, 1843, Geol. N. Y., pt. iv, p. 198, figs. 5, 5a. 

 Spirifera spmferoides Hall, 1857, Tenth Rep. N. Y. State Cab. Nat. Hist., 



p. 153, figs. 1, 2. 

 Spirifera spiriferoides Rogers, 1858, Geol. Penna., vol. ii, pt. ii, p. 828, fig. 667. 

 Athyris spiriferoides Hall, 18G0, Thirteenth Rep. N. Y. State Cab. Nat. Hist., 



p. 93, figs. 1-4. 

 Athyris spiriferoides Hall, 1867, Pal. N. Y., vol. iv, p. 285, pi. xlvi, figs. 5-31. 

 Athyris spiriferoides Keyes, 1891, Johns Hopkins Univ. Circ, vol. xi, p. 29. 

 Athyris spiriferoides Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 89, 



figs. 60, 61; pi. xlv, figs. 11-27. 

 Athyris spiriferoides Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 149. 

 Athyris spi^-iferoides Clarke, 1903, N. Y. State Mus., Bull. 65, p. 192. 

 Athyris spiriferoides Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, 



p. 353, fig. 461. 

 Not Terebratula concentrica von Buch. 



Description. — Shell varying from transversely oval to suborbicular 

 and sometimes subquadrate; hinge-line short; the cardinal extremities 

 rounded. Ventral valve moderately gibbous, often regularly convex above 

 the middle, and deeply sinuate toward the front; umbo gibbous, beak 



