FOSSILS OF THE DEVONIAN. 159 



Formation and localities. Upper horizon of the Devonian limestone; 

 The Gate, northwest of Eureka, Rescue Hill, and near the mouth of Packer 

 Basin, Eureka District, Nevada. 



Rhynchonella (Leiorhynchus) Laura Billings. 



Rhynchonella ? Laura Billings, May, I860. Canadian Journal, vol. v, p. 273, figs. 26-28. 

 Leiorhynchus multicosta Hall, December, I860. Thirteenth Ann. Eep. N. Y. State Cab. 



Nat. Hist, p. 85. 



Rhynchonella ? Laura Billings, 1863. Geol. of Canada, p. 384, figs. 418 a-c. 

 Leiorhynchus multicosta Hall, 1867. Pal. N. Y., vol. iv, p. 358, pi. Ivi, figs. 26-40. 



The Nevada examples of this species are usually broader, more convex, 

 and with stronger plications than those from the argillaceous shales of the 

 Hamilton Group of New York. These features, however, are quite as 

 prominent in the specimens from the arenaceous beds at Richmondville, 

 Schoharie County, New York, and the calcareous shales at Bosanquet and 

 Widder, Canada West. The latter localities afford specimens showing the 

 phases of development observed in the New York and Nevada examples, 

 and show the specific connection of the eastern and western forms. 



Formation and locality. Upper horizon of the Devonian limestone; 

 associated with Rliynchonella pugnus, at The Gate, northwest of Eureka, 

 Nevada. 



Genus PENTAMEEUS Sowerby. 

 Subgenus GYPIDTJLA Hall. 



Fentamerus comis Owen. 

 Plate iii, figs. 4 and 7; pi. xiv, figs. 15, 15 a, &; pi. xv, figs. 5, 5 a, &. 



Atrypa comis Owen, 1852. Eep. Geol. Surv. Wis., Iowa, and Minn., p. 583, pi. iii A, 



fig. 4. 

 Pentamerus occidentalis Hall, 1858. Geol. Iowa, vol. i, pt. 2, p. 514, pi. vi, figs. 2 a-c. 



Not Pentamerus occidentalis Hall, 1852, Pal. N. Y., vol. ii, p. 341, pi. Ixxix, 



figs. 1 a-s, 2. 

 Pentamerus galcatiform Meek & Worthen, 1866. Geol. Surv. Illinois, vol. ii, p. 325, 



(foot note.) 



Oypidula occidentalis Hall, 1867. Pal. N. Y., vol. iv, p. 380, pi. Iviii a, figs. 1-8. 

 Pentamerus comis Meek & Wortheu, 1868. Geol. Surv. Illinois, vol. iii, p. 428, pi, 



xiii, figs. 6 a-c. 



