FOSSILS OF THE DEVONIAN. 199 
Genus HYOLITHES Eichwald. 
Hyolithes, sp. (?) 
Plate vi, figs. 8, 8a. 
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 Hyolithes aclis Hall (Pal. N. Y., vol. v, pt. 2, p. 197, pl. 
xxxii, figs 22-30; pl. xxvii 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 7. 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 levis, n. sp. 
Plate vi, fig. 9. 
Shell an extremely elongate, cylindro-conical, straight or slightly 
curved tube; section circular. 
