1916.] NATURAL SCIENCES OF PHILADELPHIA. 357 



some sort. It does not seem to be a distinct race or subspecies, but it is 

 not found in other parts of the state so far as we know. The type locality is 

 some, distance from the Glenwood Springs locality, but a wide range does 

 not appear probable. We can affirm, I think, that this is not a mere 

 variation of the ordinary type, such as confluens, etc.; but whether it is a 

 distinct, race may well be doubted. Further research is needed. 



(7) depressa. This you know well. 



(8) major. Simply a large depressa; not a race. 



(9) sinistrorsa. Sinistral examples. (Brit. Naturalist. ) 



Thus, only two names are at all doubtful, and here the doubt is essentially 

 one as to the facts of nature rather than of nomenclature. (Theo. D. A. 

 Cockerell.) 



0. cooperi form maxima is a shell with about the typical shape of 

 cooperi, but of large size, the type measuring, alt. 17.6, diam. 26 mm., 

 umbilicus 5 mm., whorls 5i, more rounded than in 0. strigosa depressa. 

 There is a band at, another above the periphery, and below the 

 suture a wider, paler one interrupted into maculae. Genitalia, 

 pi. 22, fig. 1, normal for cooperi. 



The type is from Yellowstone National Park 10 miles southwest 

 of Jardine, Montana, No. 96,973 A. N. S. P., collected by E. M. 

 Kindle. Other specimens are from Grade Canyon near Cokeville, 

 Uinta Co., Wyoming, collected by Mr. J. A. G. Rehn. One of these 

 measures alt. 17.7, diam. 26 mm. In addition to the markings 

 described above, it has a few faint brown circular lines on the base. 



Form iowensis Pils. is quite small, height 7.7, diam. 11.4, umbilicus 

 2.6 mm., with 4f whorls. There is a reddish band just under the 

 periphery, and the initial whorl is very convex and smooth. It is 

 from the loess, type-locality, Iowa City, Iowa. It probably stands 

 close to stantoni, which still exists in an environment perhaps not 

 very unlike the loess climate of Iowa. 



0. p. wasatchensis is so peculiarly modified that one is strongly 

 inclined to give it specific rank. The elevated spire, the compactly 

 coiled whorls and the peripheral carina all differentiate it from 

 0. peripherica. Yet 0. p. newcombii stands almost intermediate 

 between wasatchensis and peripherica. It does not differ from the 

 coarsest examples of the latter in form or ribbing, but it has a delicate 

 peripheral keel which continues as far, usually, as the last whorl, 

 whereas 0. peripherica has no keel in the later neanic and the adult 

 stages. Possibly both newcombi and wasatchensis may eventually 

 be ranked as species; but until further collections can be made, 

 I leave them associated with 0. peripherica, with the note that at 

 present we do not have actual evidence of intergradation. 



In this connection we may allude to the status of 0. pygmcea, 

 which may turn out to be a subspecies of 0. peripherica; yet here 

 again, evidence of intergradation is wanting. 



