STANTON.] 



VOLUTID^. 157 



and slightly reflexed; inner lip with a very thin callus. The pillar is 

 slightly arched with two distinct folds, the anterior of which is the 

 stronger, and faint indications of two others behind them. 



Length of an average specimen, 77 mm ; greatest breadth, 24 ,nra . Other 

 specimens show that the species attained a considerably greater size 

 and sometimes had a more robust form. 



One imperfect specimen of which a figure is given (PI. xxxin, Fig. 10) 

 differs somewhat in the character of the ornamentation, the transverse 

 costse being shortened into rounded nodes. Possibly it belongs to a 

 different species ; but the other specimens that certainly belong together 

 show considerable variation in this character. 



Forms similar to this have been referred to Fasciolaria by Stoliczka 

 and others, but they seem to belong to the Volutidse. It is true, how- 

 ever, that in the Oretaceousthe lines can not be sharply drawn between 

 the Volutidse and the Fasciolariidse ; and we find different authors 

 assigning such forms in some cases to Fasciolaria and in others to 

 Volutilithes and other volutoid genera. Some forms of Piestochilus 

 which was proposed as a subgenus under Fasciolaria by Meek are not 

 very different in general aspect from this species. 



Locality and position. — Abundant in the Pugnellus sandstone on 

 Williams creek and in Poison canyon ; it also occurs at other places 

 in Huerfano park, and at about the same horizon at Eattlesnake butte, 

 18 miles east of Walsenburg and on the Arkansas river, 20 miles above 

 Pueblo, Colorado. 



EOSTELLITES GRACILIS n. sp. 



PI. xxxiv, Figs. 1-3. 



Shell large, slender, fusiform, consisting of about seven volutions, 

 the last of which comprises about three-fourths of the total length of 

 the shell; whorls convex and rounded in the middle, constricted pos- 

 teriorly, the body whorl gradually narrowed into the moderately long 

 canal; suture linear, appressed, in some examples apparently glazed 

 by a thin deposit of callus. Surface marked by rather distinct lines of 

 growth and by curved transverse costse that cross only the convex por- 

 tion of the whorl leaving the posterior constricted portion smooth. 

 The costae are most prominent on the upper part of the spire, gradually 

 becoming more distant and less conspicuous and disappearing entirely 

 on the last whorl or sometimes earlier. One specimen also shows traces 

 of numerous very fine revolving lines on the earlier whorls. 



Aperture long and narrow, posteriorly acute and slightly emargi- 

 nate; outer lip thin, sharp, and smooth within; inner lip with a thin 

 deposit of callus that seems sometimes to spread over the spire in a 

 thinner glaze. Pillar nearly straight with three very strong, subequal, 

 oblique plaits near the middle. 



Length of a medium-sized specimen, 110 mm ; greatest breadth, 28 mm . 

 The largest of the figured specimens, which lacks the apex of the spire 



