FOSSILS OF THE DEVONIAN. 



Genus HYOLITHES Eichwald. 



199 



Hyolithes, sp. (?) 

 Plate vi, figs. 8, 8 a. 



Form elongate, triangular, tapering regularly and gradually to an acute 

 extremity. Transverse section subtriangular, slightly convex on the ventral 

 side. Dorsal angle obtuse. Breadth and depth as two to one. Ventral face 

 gently convex, arching slightly from the apex to the aperture Dorsal face 

 with a longitudinal concavity about equal to the convexity of the ventral 

 face; strongly arched transversely. The aperture is not preserved, but was 

 probably oblique, as in allied species. 



Surface of shell unknown, as the only two specimens obtained are in 

 the form of casts. This species is very closely allied, if not identical, in 

 general form with Hyolitlies aclis Hall (Pal. N. Y., vol. v, pt. 2, p. 1JJ 1 ?, pi. 

 xxxii, figs. 22-30; pi. xxxii A, figs. 23-25) from the Hamilton Group of New 

 York The finding of specimens preserving the shell may show differences 

 that are not now apparent, and for this reason no specific identification is 

 attempted. 



Professor Hall calls attention to the small number of species of Hyo- 

 lithes in American Paleozoic strata as compared with other Paleozoic coun- 

 tries, and also the limited geographic range of the American species. All 

 the collections made during the past few years from the Paleozoic formations 

 of the Rocky Mountains and westward have offered no new well-determined 

 forms, and but one species is known at present from above the Cambrian, 

 or first, fauna Owing to the restricted range of the Devonian species of 

 New York, we hesitate to identify this species with H. aclis, or to define it as 

 a new species, until better specimens are collected. 



Formation and locality. Lower Devonian of Atrypa Peak, Eureka Dis- 

 trict, Nevada. 



Genus COLEOLUS Hall. 



Coleolus laevis, n. sp. 



Plate vi, fig. 9. 



Shell an extremely elongate, cylindro-conical, straight or slightly 

 curved tube ; section circular. 



