wiuTE.] LAKAIIIE FOSSILS OF DANFOETH HILLS. 213 



west of tlie Eocky IMoimtams 5 but its position east of the mountains 

 is apparently near the base of tlie group. 



8. Corhula undij'era Meek. 



This species was described by Meek in the Annual Report of the 

 United iStates Geological and Geographical Survey of the Territories 

 for 1872, p. 513, from the Laramie strata at Eock Springs in the valley 

 of Bitter Creek. In Powell's Eeport on the Geology of the Uinta Moujit- 

 ainSj p. ll'l), 1 described another form under the name of C. subiindifera 

 from a higher horizon of the Laramie strata of the same Aalley, which I 

 now regard as only a variety of ]Mr. Meek's species. The original variety 

 has been found only at Eock Springs and at the Danforth Hills locality. 

 The variety subundifera was originally fomid at Pomt of Eocks in 

 Bitter Creek Vallej', and I have also recognized it among' some fossils 

 brought from Upper Kanab, Southern Utah, by Professor Powell. The 

 two varieties thus seem to be quite constant. 



9. Melania icyomingensis Meek. 



The ^^ide geographical distribution of this species, as well as its char- 

 acteristics, has already been commented on under the head of notes on 

 the Laramie fossils of Crow Creek' A^'alley. Its occurrence here not only 

 adds to our knowledge of its distribution, but also to that of its vertical 

 range in the Laramie Group. Its position at the original locality in 

 Bitter Creek Valley, and also at that of Yampa Valley, is near the top 

 of the gToup. At the Danlbrth Hills locality its position is near the 

 base of the group, showing the kno"UTi vertical range of the species to 

 be about 3,000 feet. It is a noticeable fact that all the associates of this 

 species at the Danforth Hills locality are brackish- water, or perhaps in 

 part marine species, none bemg purely or exclusively of fresh- water habi- 

 tat. It is also a singular fact that while other fresh- water forms are some- 

 times associated with it, some of its associates at all the localities where it 

 has been discovered are brackish-water forms, or those that may have 

 inhabited both fresh and brackish waters. The characteristics of the 

 shell are such as to scarcely admit of a doubt that it is either a true 

 Melania or a very closely allied form. 



10. Odontohasis ? formosa. 



Only a single examx^le of this species was discovered. It is imperfect, 

 and perhaps does not belong to that genus, to which it is referred pro- 

 visionally. It is published in the Bulietiu of the United States Geolog- 

 ical Survey, vol. iv, p. 718, and also in this voliune, with a figure. 



11. CijtJiennaf 



In the fine-gTained indurated reddish shales of this locality are nu- 

 merous casts of an Ostracoid crustacean which I refer provisionally to 

 Cytherina. These are the first examples of that order of crustaceans, 

 so far as I am aware, that have been discovered in strata of the Laramie 

 Group. 



12. FisJh remains. 



A few cycloid scales were also found in these shales, which, except a 

 few shuilar examples found in Bear Eiver Valley, are the only tisli re- 

 mains discovered by myself in Laramie strata ; but there seems to be no 

 reason why fishes may not have existed abundantly during that i)eriod. 



The absence of the Ostrca here is noticeable, and is jnobabiy due to 

 the uncongeniality of habitat that was produced by the fine sediment 

 which now constitutes the shales. 0. glabra was fouiid further doAvn the 

 valley of White Elver m strata fnilj as near the base of the groux) as 



