DESCKIPTIOWS OF SPECIES. 465 



Although the shell, aside from the ornamental feature ]ust mentioned, appears 

 to be plain, j-et, thinking that such characters might be obscured by the exfoliated 

 condition which pi'evails, 1 at first identified these specimens as Pleurotomaria? 

 splronema M. and W. Thej^ much resemble that species in shape, and might readily 

 be mistakenly referred to it in their present condition. M_y material was compared 

 with exfoliated specimens of PI. ? sjpironema from jMenard County, 111. (identi- 

 fication by Worthen), and close agreement was found. The one fairly constant 

 character that I can point out is that in PI. ? spironema the beading is stronger and 

 more elongate in a direction perpendicular to the suture. 



Keyes places this species wdth Pleurotomaria because he thinks that some ti*ne 

 it will be shown to possess a slit band, though the type specimen seems to be without 

 that character. I do not see, however, that matters are improved by this course, as 

 a Pleurotomaria without a slit band is certainly more anomalous than a Naticopsis 

 with a low of ornamental nodes. Accordingly I have replaced it with the genus to 

 which it was ascribed by White. 



Locality and horizov. — San Juan region (stations 2231, 23i2, 23i5); Hermosa 

 and Rico formations. 



EUOMPHALUS Sowerby, 1812. 



EuoMPHAi^us CATiLLOiDES Conrad. 



1842. Inachus catilloidei!. Conrad, Acad. Nat. Sci. Philadelphia, Jour., (1), vol. 8, p. 273. 



Coal Measures. 

 18.58. Euomphalus rugosu.^. Hall, (ieol. Surv. Iowa, vol. 1, pt. 2, p. 722, pi. 29, figs. 14a-c. 



Coal Measures: Illinois. 

 1866. Scrpula (Spirorhk) planorhiies. Geinitz, Carb. und Dyas in Nebraska, p. 3, lab. 1, fig. 6. 



Upper Coal Measures: Nebraska. 



1872. Straparollus {Euomphalus) nigosus. Meek, U. S. Geol. Surv. Nebraska, p. 230, pi. 6, figs. 5a, b 



pi. 11, figs. 4a, b. 

 Upper Coal Measures: Nebraska City, Rock Bluff, Aspinwall, arid Cedar Bluff, Nebr. 

 Coal Measures: Kansas; Missouri; Iowa; Illinois. 



1873. Straparollus {EuomphaluK) subrugoms. Meek and Worthen, Geol. Surv. Illinois, Kept., vol. 5, 



p. 607, pi. 29, fig. 11. 

 Coal Measures: Springfield, 111. 



1874. Euoinphahts rugosus. Meek, Am. Jour. Sci., (3), vol. '7, p. 583. 

 Coal Measures: Illinois. 



1884. Euomphalus {Strnparolluf!) subrugosus. Walcott, U. S. Geol. Surv., Mon., vol. 8, p. 255, pi. 18, 

 fig. 19. 

 Lower Carboniferous: Eureka district, Nevada. 

 1884. Eaoiiiphalus i-ugosus. White, Geol. Surv. Indiana, 13th Kept., p. 161, pi. 32, figs. 11, 12. 



Coal Measures: Indiana. 

 IStS. Euomphalus rugusus. Keyes, Acad. Nat. Sci. Philadelphia, Proc, p. 241. 

 Lower Coal Measures: Des Moines, Iowa. 

 14364— No. 16—03 30 



