LOWER CARBONIFEROUS FOSSILS. 545 



Dielasma rowleyi Hall and Clarke 1 (11011 Worthen) and Terebratula 

 gorbyi S. A. Miller 2 are closely related forms, but I have not been able to 

 examine them personally. 



It is probable that I), utah will prove synonymous with I), burling- 

 tonense White, of the same geologic horizon, but the scanty material of the 

 former species, joined to the very inadequate description of the latter, ren- 

 ders it impossible to determine this point. 



Specimens of I), oiirlingtonense White from the Cuyahoga shale as 

 exposed at various points in Summit and Medina counties can not be 

 distinguished from T). utah, by any characters that I have been able to 

 discover. 



Formation and locality: Madison limestone, limestone bluff north 

 of Little Sunlight Creek, Absaroka Range, 600 feet above the stream; 

 Arnold Hague. East side of Gallatin River, west of Electric Peak ; Crow- 

 foot Ridge, Gallatin Range, bed 28 ; J. P. Iddings and W. H. Weed. 

 Lower Carboniferous, Cottonwood Divide, Wasatch Range, Utah. 



SPIRIFERINA d'Orbigny, 1828. 



Spiriferina solidirostris White. 



PI. LXXI, fig. !()«. 



Spirifer solidirostris White, 1860: Jour. Boston Soc. Nat. Hist., Vol. VII, p. 232. 

 Spiriferina solidirostris White, 1S62: Proc. Boston Soc. Nat. Hist., Vol. IX, p. 24. A. 

 Winchell, 1865: Proc. Acad. Nat. Sci. Philadelphia, p. 120. 



This is not a common species in the Yellowstone National Park. It 

 has been observed at a number of localities, but is represented by only one 

 or two specimens at each. These correspond so entirely with S. solidirostris, 

 as far as characters are indicated, that I refer them very confidently to 

 White's species. The area, shape of shell, number and character of 

 plications, and surface ornamentation are exactly as White has described 

 them. The largest specimen, a ventral valve of unusual size, measured 

 21.5 mm. in width by 12.5 mm. in length; but the one figured (PI. LXXI, 

 fig. 10fl), which measures 15 mm. in width by 12 mm. in length, is perhaps 

 nearer the average. 



1 Hall and Clarke, 1895: Pal. New York, Vol. VIII. Pt. II, PI. LXXXI, figs. 27, 28. 



•S. A. Miller, 1892 (for 1891) : Seventeenth Rept. State Geologist Indiana, p. 687, PI. XIII. figs. 3, i. 



MON XXXII, PT II 35 



