FOSSILS OF THE DEVONIAN. 



197 



In New York it is associated with Styliola fissureUa, 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, pi. 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 fissureUa, 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. 



Tentaoulites attenuates Hall (Pal. N. Y., vol. v, pt. 2, p. 170, pi. 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 bellulua Hall? (Pal. N. Y., vol. v, pt. 2, p. 169, pi. xxxi, figs. 15-18; and pi. 

 xxxi A, figs. 48-51). 



There occur in association with the preceding species a few specimens 

 that are closely allied to T. 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 fissureUa Hall (Pal. N. Y., vol. V, pt. 2, p. 178, pi. 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 fissureUa var. intermittens Hall (Pal. N. Y., vol. V, pt. 2, p. 177, pi. xxxi A, figs. 

 11-17.) 



This elongate form is represented in the upper strata at The Gate, 

 northwest of Eureka, Eureka District, Nevada. 



