CARBONIFEROUS PERIOD. 139 



Mr. Meek, in his Paleontological Keport for the United States Geological 

 Surveyor Nebraska, lias pointed out the close relationship of the more 

 compact forms of this species with S. odopUcata Sowerby from the Sub- 

 carboniferous strata of Europe, but expresses a doubt of its specific identity 

 with the European shell. That it is really distinct from 8. odopUcata is now 

 apparently proven by the discovery in strata of the same period, and among 

 the associates of S. Kentuckensis, of a species that seems to be unquestionably 

 identical with the former species, and as certainly different from the latter. 



Position and locality. — This species is quite a common one in the Car- 

 boniferous strata of Kentucky, Illinois, Missouri, lowfi, Nebraska, Kansas, 

 and Texas ; but I am not aware that it has ever been discovered in strata 

 of the Subcarbouiferous period. The collections contain it from strata of 

 the Carboniferous period from near Santa Fe, New Mexico, at Meadow 

 Creek, south of Fillmore, Utah, and Camp Apache, Arizona. The species 

 is represented by an iinexpectedl}^ small number of specimens. 



Spiriferina octoplicata Sowerby. 



Plate X, fig. 8 a, h, and c. 



Spirifer octoplicatiis Sowerby, 1827, Mineral Couchology, 120. 



Spirifer cristaUis von Buch, 1837, Ueber Deltbyris, 39. 



Spirifer cristahis McCoj^, 1855, Synopsis Garb. Foss. Ireland, 133. 



Spiriferina cristata var. octoplicata Davidson, 1857, Monog. British Garb. Bracbiopoda, 



38. 

 Spiriferina spinosa var. campestris White, 1871, Expl. & Surv. west 100th Merid., 



Prelim. Report Invert. Foss., 21. 



Shell rather under medium size, suboval or somewhat tetrahedral in 

 outline, broader than long, more or less gibbous ; hinge-line extended, not 

 mucronate, but usually a trifle shorter than the greatest breadth of the 

 shell ; valves of almost equal capacity. 



Mesial fold of the dorsal valve narrow, plain, distinctly defined from 

 front to beak, elevated at the front of the more gibbous examples ; beak of 

 the valve slightly projecting over the cardinal margin. Mesial sinus of the 

 ventral valve plain, narrow or of moderate width, distinctly defined from 

 front to beak, sometimes extended much upward at the front ; beak of the 

 valve prominent, incurved, its area moderately high and gently arching. 



