152 SYSTE:\rATic Paleoxtology— Middle Devoxian 



Eock, W. Va. ( ?) : 1 mile nortli of Eomnev, W. Ya.: on the Eomney- 

 HangJBg Rock Road about i mile north of Eomney, W. Va. ; W. Ya. side 

 Potomac Eiver 3 and 4 miles soiith of Cumberland. 



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

 American Museum of Natural History. 



ClIONETES SETIGER (Hall) 



Plate XI, Figs. 22-25 



Strophomena sctigera Hall, 1843, Geol. N. Y., pt. iv, p. 180, fig. 2, p. 222, fig. 3. 

 Chonctes setigera de Koninck, 1847, Recher. Anlmaux Foss., vol. i, p. 215, 



pi. XX, fig. 7. 

 Chonetes setigera Hall, 1867, Pal. N. Y., vol. iv, p. 129, pi. xxi, fig. 2; p. 142, 



pi. xxii, figs. 1-5. 

 Chonetes setigera Hall and Clarke, 1892, Pal. N. Y., vol. viii, pt. i, pi. xvi, 



figs. 2, 5, 19. 

 Chonetes setigerus Schuchert, 1897, Bull. U. S. Geol. Surv. No. 87, p. 178. 

 Chonetes setiger Clarke, 1904, N. Y. State Mus., Mem. 6, p. 376. 

 Chonetes setigerus Grabau and Shimer, 1907, N. Am. Index Fossils, vol. ii, p. 



237, fig. 289a. 



Description. — Shell semielliptical ; the hinge-line equaling the greatest 

 width of the shell, and rarely extending beyond. Ventral valve moder- 

 ately convex, rarely a little gibbous in the middle; umbo scarcely rising 

 above the hinge-line; the greatest elevation is above the middle of the 

 shdl and it gradually slopes toward the front and lateral margins be- 

 coming flattened on the cardinal angles; the cardinal margin generally 

 has three slender tubular spines on each side of the apex, which are bent 

 a little outward as they leave the shell, and then rise almost vertically, 

 or with a slight curve from the direction of the hinge-line. The striae 

 are slender rounded or subangular, increasing by bifurcation and inter- 

 calation so that there are from 36 to 50 on the margin. On well pre- 

 served specimens the radial striae are crossed by fine concentric ones. 



Among the Maryland specimens there are forms similar to those 

 figured by Hall on plates 21 and 22, vol. iv, Palseontology of New York; 

 and other specimens somewhat larger which agree with similar forms 

 from the Hamilton and Ithaca formations of New York which have 

 been referred by H. S. William.^ and other paleontologists to this 



