FOSSILS OF THE CAEBONIFEEOUS. 



219 



Pancake Range, where numerous examples occur that may be referred to 

 either form, according- as the spine bases are more or less prominent, or the 

 shell contracted or extended laterally. On comparing these and specimens 

 of each variety from the Mississippi Valley it seems impossible to avoid the 

 conclusion that they are one and the same species. 



Fig 12, plate xviii, is taken from a Chester limestone specimen, and 

 the adjoining fig. 13 from a specimen found in the Upper Carboniferous 

 limestone of the Eureka District. Comparing these and also the specimens 

 with Mr. Davidson's figures of Spiriferina cristata Schloth., 1816r= octo- 

 plicatus Sowerby, 1827, it appears that we have another very variable spe- 

 cies that has a great vertical range and an extended geographic distribu- 

 tion. Dr. White (Expl. and Surv. West 100th Merid., vol. iv, pt. 1, p. 140, 

 187 .") regards Spiriferina Kentuckensis and S. octoplicata as distinct species, 

 but with the evidence now accessible I should be inclined to consider them 

 and also spinosa as varieties of one and the same species 



In the Devonian White Pine shale of the White Pine Mining District 

 there is a form that in its plications is similar to S. cristata, and in surface 

 markings it is very much like S. insculpta Phillips. It occurs at the summit 

 of the Devonian, and is referred to S. cristata Mr. Davidson has recognized 

 the species in both the Middle and Lower Devonian (British Devonian 

 Brachiopoda, p. 123). 



Formation and localities. In the Lower Carboniferous on the east slope 

 of a small conical hill on the east side of Secret-canon-road Canon and in 

 the Upper Carboniferous limestone of the western slope and foothills of 

 Diamond Peak, Eureka District, Nevada. 



Genus SYRINGOTHYRIS Winchell. 

 Syringothyris cuspidata Martin (Sp.). 



Anomites cuspidatus Martin, 1796. See Davidson's Mon. Brit. Carb.Brach., p. 44, and 



supplement, vol. iv, p. 278, 1880. 

 Spirifer cuspidatus f Meek, 1877. Geol. Expl. Fortieth Par., vol. iv, p. 87, pi. iii, figs. 



11, 11 a. 



Mr. Meek cites this species from above the Devonian of the White Pine 

 Mountains, Nevada. It is quite abundant on Richmond Mountain in one 



