FOSSILS OF THE DEVONIAN. 



103 



prominent spinulose crests, extending through the whole length of the 

 channels. Transverse diaphragms partly simple and complete, partly in- 

 complete, represented by lateral squamiform, horizontal leaflets. Pores 

 large and very numerous." 



The species is represented by a single portion of a stem 28 mm in diam- 

 eter; the polygonal, unequal orifices are about l mra in diameter and present 

 the character given them by the author of the species, as do the diaphragms 

 and large pores. Although there is no evidence of its being a branching 

 form, as there is but a portion of a stem in the collections, it seems extremely 

 probable from the close specific characters of the portion we have that it is 

 specifically identical with the Upper Helderberg- species. 



Formation and locality. Lower horizon of the Devonian limestone, 

 central portion of Gray's Canon, Eureka District, Nevada. 



Syiingopora Hisingeri Billings. 1859. Call. Jour., 11. Ser., vol. iv, p. 116. 



In New York, Canada, Indiana, etc., this species occurs in the Upper 

 Helderberg limestones, but at The Gate, northwest of Eureka, it is associ- 

 ated with fossils of the Chemung horizon in the Upper Devonian beds. 

 Numerous fine specimens were found, so that the specific identification 

 hardly admits of question. 



Syringopora perelegans Billings. 1859. Can. Jour., D. Ser., vol. iv, p. 117. 



Specimens referable to this species were found in the Lower Devonian 

 beds at Lone Mountain, and also at the summit of the formation at The Gate, 

 northwest of Eureka, showing its range through the entire Devonian forma- 

 tion. It is extensively distributed in the strata of the hills east and west 

 of Yahoo Canon. At the east it occurs in the Upper Helderberg limestones. 



Aulopora serpens Goldfuss? See Geol. Surv. Michigan, vol. iii, pt. 2. 1876. 



In size, manner of branching and reuniting of the tubes, this species 

 of Aulopora from the Lower Devonian beds of Gray's Canon corresponds 

 to the descriptions and illustrations given of the American form identified 

 with that species, and a comparison with the figures given by Goldfuss 

 indicates that this identification is correct, although his figures show a some- 

 what smaller and less robust form. 



