FOSSILS OF THE DEVONIAN. 



101 



ous transverse diaphragms, the general size of the cells, and the mode of 

 growth, the species is similar to the European form of F. basaltica. 



Formation and localities. Lower horizon of the Devonian limestone at 

 Lone Mountain, 18 miles northwest of Eureka; at the head of the Reese 

 and Berry Canon, and on the ridge of Atrypa Peak, Eureka District, Nevada. 



Favosites, n. sp. 



Corallum growing in hemispherical or irregularly formed masses made 

 up of small tubes varying in size from l mm to 1.5 mm , which are without any 

 distinct arrangement in relation to size, the smaller cells occurring together 

 or with the larger interspersed among them. On the upper surface of the 

 corallum the cell walls are thickened and have a beaded appearance which 

 is not observed in a transverse section of the tubes a short distance below 

 where the walls are strong and the tubes distinctly polygonal and not 

 rounded as at the apertures. Transverse diaphragms entire, closely ar- 

 ranged or separated up to a distance equal to an entire diameter of the tube 

 Mural pores not well determined, but there is apparently a single row of 

 rather large size on each side. 



The largest fragment obtained has a depth of 8 cm , and the diameter of 

 the entire corallum was from 15 cm to 20 cm . 



In the character of the cell -walls at the surface of the corallum, the 

 diaphragms in the tubes, and form of growth, this species is not unlike 

 Favosites f Argus Hall, of the Hamilton Group of New York, but in the 

 small size of the cells, and the absence of the very large cells among the 

 smaller ones in the latter species, it is very distinct from it. 



Formation and locality. Lower horizon of the Devonian limestone at 

 Lone Mountain, 18 miles northwest of Eureka, Nevada. 



Fistulipora, sp. ? 



Silicified specimens of a well-characterized species of this genus occur 

 in association with fossils of the Upper Helderberg horizon. Its specific 

 relations are not yet determined. 



Formation and locality Devonian limestone, lower horizon, Atrypa 

 Peak Ridge, Eureka District, Nevada. 



