STANTON.] 



VOLUTID.E. 155 



the surface ornamentation consists of numerous strong, granular revolv- 

 ing lines, usually alternating with finer ones and crossed by distinct 

 lines of growth. Aperture elongate ovate, suddenly narrowed and 

 slightly produced above to form a short posterior canal and more grad- 

 ually contracted below into the rather broad anterior canal. 



Outer lip thin and slightly dentate within; inner lip comparatively 

 thin, forming a broad thin glaze on the body whorl above, but thicken- 

 ing and narrowing below until it is free from the columella, leaving a 

 distinct and deep umbilicus. There is a single oblique fold on the 

 columella. 



Length of one of the types, 77 ,n,n ; greatest breadth, 49 mm . 



Compared with Pyropsis bairdi M. & H., which seems to be the most 

 closely related described form, this species has a shorter and broader 

 anterior canal, a larger umbilicus, only two carinas on the body whorl 

 instead of three, and stronger revolving sculpture. Besides, our spe- 

 cies has the short posterior canal and the dentate outer lip, both of 

 which are entirely lacking in P. bairdi. In some respects it approaches 

 Eapa cancellata Sowerby, from the Cretaceous of southern India. 



Locality and position. — In the Pugnellus sandstone on Williams creek 

 and in Poison canyon, Huerfano park, Colorado. Some very imper- 

 fect casts from about the same horizon at Coalville, Utah, probably 

 belong to this species. 



VOLUTID^E. 

 Genus EOSTELLITES Conrad. 



This genus was proposed in 1855 with Eostellitcs texana (= Voluti- 

 lithes navarroensis Shumard) as the type. In 1876 Gabb gave the 

 name Volutoderma to the group to which this species belongs. In his 

 recent discussion of the Volutidre Dr. W. H. Dall 1 has more fully char- 

 acterized the genus and restored Conrad's earlier name. His descrip- 

 tion is as follows : "The genus Eostellites is characterized by a usually 

 thick shell with a tendency to cancellated sculpture of distant narrow 

 ridges, more or less nodose at the intersections; by an acute apex and 

 trochoid, minute nucleus; by a tendency to a notch or sulcus in the 

 outer lip near the suture; and by the presence of several well- differen- 

 tiated plaits on the pillar. A few species are thin and the form is ex- 

 tremely variable. The surface is not glazed, the pillar is nearly 

 straight, and the incremental lines are conspicuous." 



Dr. Dall has kindly examined the three species described below and 

 he regards all of them as members of this genus. EosteUites gracilis 

 differs from the type of the genus in that the revolving sculpture is 

 obsolete and the spire is glazed, at least in some examples, but these 

 features are not considered of generic importance. 



» TranB. Wagner Free Inst, of Sci., rol. 3, 1890, pp. 71, 72. 



