108 BULLETIN 64, UNITED STATES NATIONAL MUSEUM. 



mine. The Carboniferous and older strata are, in Claiborne County, so near each 

 other and so often in contact, that I am not able to state its true geological age. 



Observations. — Doctor Troost's type of this species was at first 

 referred to Melonites giganteus Jackson. The specimen has recently 

 been sent to Doctor Jackson who considers it a distinct species. In 

 accordance with the views of this high authority Troost's species is 

 retained, but in the absence of the types of both species I am unable 

 to say in what respect M. granulatus differs from M. giganteus Jack- 

 son. Troost's specimen has extremely thick plates and a strongly 

 tuberculate surface. The plates of the ambulaeral area are too much 

 eroded to reveal their outlines, but pairs of pores show distinctly on 

 many of them. The fragment apparently comes from near the 

 ambitus of a large specimen. 



Formation and locality. — Mississippi . Cumberland Gap, Ten- 

 nessee. 



Cat. No. 39909, U.S.N.M. 



Cidarites tennesseex. — This name is given to a number of spines 

 not represented in the collection. According to the figures, plate 8, 

 figs. 2-5, they probably belong with the Cidarida?, but our informa- 

 tion is too meager to place them with the proper species. 



