CARBONIFEROUS SPECIES 91 



Length, ].90 inches; breadth, 2 inches; convexity, 1.30 inches. 



This fine species may be compared with S. hisulcatus of Sowerby, some 

 varieties of which (especially those with broad depressed costse) it more or 

 less nearly resembles. It seems, however, to be always longer in propor- 

 tion to breadth, and is much less variable in form. The most reliable dif- 

 ference observable, however, is the beautifully-granulated surface of our 

 species. I know of no nearly similar American shell with which it is neces- 

 sary to compare it. 



Locality and position. — Light-colored Carboniferous limestone, at lati- 

 tude 40° N., longitude 115° 20' W.; Colonel Simpson's collections. 



Spirifeu (Trigonotrbta) cameratus, Morton. 



Plate 9, figs. 2, 2 a. 



Spirifer cameratus, Morton (1836), Am. Jour. Sci. and Arts, XXIX, 150, pi. 2, fig. 3. — 

 Hall (1856), Pacific R. R. Report, III, 102, pi. 2, figs. 9, 12, and 13; and (1858) 

 in Iowa Geological Report, I, part ii, 709, pi. xxviii, fig. 2. — Meek (1876), in 

 Col. Simpson's Keport Expl. across the Great Basin of Utah, 353, pi. ii, figs, 

 3 a, h. 



Spirifer Meusehaclianus, Roemer (1852), Kreid. von Texas, 88, pi. 11, figs. 7 «, 6, c. 



tSpirifer triplicatus, Hall (1852), Stansbury's Report of Salt Lake Expl. Expedition, 410, ' 

 pi. 2, fig. 5 (by error pi. 4). 



? Spirifer fasciger, Owen (1852), Report Wisconsin Iowa and Minnesota, pi. 5, fig. 4 

 (Keyserling? (1846.) 



Spirifer striatus var. triplicatus, Marcou (1858), Geol. N. Am., 49, pi. vii, fig. 3. 



Spirifer cameralus var. Kansasensis, Swallow (1867), Trans. Saint Louis Acad. Sci., II. 



# Spirifera camerata, Derby (1874), Bull. Cornell Univ., I, No. ii, 13, pi. i, tigs. 1-9, and 14. 



The specimens that I have referred to this common species are all more 

 or less broken or distorted ; but, so far as their characters can be made out, 

 they seem to agree so nearly with characteristic examples of Morton's species 

 from the Coal-Measures of the Mississippi Valley, that I have scarcely any 

 doubts of their identity. They all have the peculiar fasciculated character 

 of the costae, so characteristic of S. cameratus, more or less marked, while in 

 some of them it is well defined. They seem to have the mesial fold some- 

 what less prominent, and the lateral slopes less compressed than we usually 

 see in S. cameratus; but these are more or less variable characters in that 

 species. 



Locality and position. — Light-colored Carboniferous limestone, at Fos- 



