100 PALEONTOLOGY OF THE EUREKA DISTRICT. 



Genus STROMATOPORA Goldfuss. 



One or two species of this genus occurs very abundantly at several 

 horizons throughout the Devonian formation. They are not in a condition 

 to admit of specific determination without first having a series of thin sec- 

 tions prepared and a special study made in connection with other species, 

 the material for which is not available at present. 



ACTINOZOA. 



Owing to the meagerness of the material representing some of the spe- 

 cies, and the fact that much larger collections may be obtained for future 

 study, it is not considered best to attempt to illustrate and describe this 

 group until it can be done in a more satisfactory manner than at present. 

 A short note of each of the identified species and a notice of such as are con- 

 sidered new and undescribed is given. The specific identifications were 

 chiefly made by a direct comparison of the Nevada specimens with authen- 

 ticated specimens in the beautiful and extensive collection of the New York 

 State Museum and the private collection of Prof. James Hall. 



Favosites hemispherica Yandell and Shumard. See Geol. Surv. Michigan, vol. iii, pt. 2, 

 p. 25, 1876. 



Several specimens of the cylindrical form of growth occur in the collec- 

 tions, but none of the large hemispheric or turbinate forms so characteristic 

 of the species in the Corniferous limestone of New York, Ohio, Canada, etc. 



Formation and localities. Lower horizon of the Devonian limestone at 

 Lone Mountain, 18 miles northwest of Eureka, and also at the head of the 

 Reese and Berry Canon, Eureka District, Nevada. 



Pavosites basaltica Goldfuss. 1829. Petref. Germ., vol. i, p. 78. 



A comparison with the figures given by Goldfuss, and also with a speci- 

 men from Silesia, shows a very close specific resemblance between them 

 and the Nevada specimens, and one of the latter appears to be specifically 

 identical in all its characters with this species. Other specimens vary in the 

 size of the cells from 2 mm , the usual size of those in F. basaltica, to 3 mra ; 

 smaller cells not over l mm in diameter occur on the same specimen. In the 

 presence, however, of a single row of pores on each side of the cells, numer- 



