FOSSILS OF THE DEVONIAN. 197 
In New York it is associated with Styliola fissurella, a species that occurs 
with it at all the localities known in Nevada. 
Tentaculites scalariformis Hall (Pal. N. Y., vol. v, pt. 2, p. 167, pl. xxxi, figs. 3-11). 
The identification of this species is by the characters of the internal 
mold, the robust form, and the shape and regularity of the annulations. It 
has not been observed in association with Styliola fissurella, or other congen- 
eric species. 
Professor Hall states that this species has a geographic range of over 
700 miles as known to him, being found in the strata of the Upper Helder- 
berg limestone in New York, Ohio, and Indiana. 
Tentaculites attenuatus Hall (Pal. N. Y., vol. v, pt. 2, p. 170, pl. XxXi, figs. 19, 20). 
The Nevada specimens of this species are the same in the character of 
the surface markings and the irregularity of the annulations on the slender 
tube, but the species does not appear to have been as gregarious in habit 
as in the Hamilton Group. 
Tentaculites bellulus Hall? (Pal. N. Y., vol. v, pt. 2, p. 169, pl. xxxi, figs. 15-18; and pl. 
xxxi A, figs. 48-51). 
There occur in association with the preceding species a few specimens 
that are closely allied to 7. bellulus. They have the same numerous, sharp, 
regular annulations and attenuate tube, but differ in being smaller, and in 
the absence of the surface markings mentioned by the author of the species. 
Genus STYLIOLA Le Sueur. 
Styliola fissurella Hall (Pal. N. Y., vol. v, pt. 2, p. 178, pl. xxxi A, figs. 1-30). 
It does not appear to be possible to separate this minute form from the 
species as it occurs in New York. It ranges through the fossil-bearing 
Devonian limestone from the lower horizon at Lone Mountain to the highest 
beds at The Gate, northwest of Eureka, Nevada. 
Styliola fissurella var. intermittens Hall (Pal. N. Y., vol. v, pt. 2, p. 177, pl. xxxi A, figs. 
11-17.) 
This elongate form is represented in the upper strata at The Gate, 
northwest of Eureka, Eureka District, Nevada. 
