DESCRIPTIONS OF SPECIES. 



Many works dealing- with the geology of Colorado contain lists of fossils \-arvin<>- 

 m extent and in the degree of care with which thej'^ appear to have l)ecn prepared, 

 and the evidence thus conveyed I have used as far as it seemed safe and as far as it 

 bore upon my subject. 



Believing, however, that contradictions i-esult from compilations of lists of 

 species made b}^ different individuals at different times, I shall employ in this por- 

 tion of ni}' discussion onl}^ such evidence in the way of collections of fossils as has 

 come under my own observation. Deserving some wl at different considei'ation are 

 those works o-f paleontologic rather than geologic character which carr}- authority 

 for the identifications made in them in the shape of descriptions and illustrations of 

 species. In works of this sort the following species have been cited from Colorado: 

 Eujiheinits subjMpUlosus" PrisrnojX'ra triaiigidata,^ LopliopTiyUum profundum vai-. 

 sauridens^" Marginifera, mtiricata,'^ Cleiothyrls orMcidaris,'- Euconispira taggart// 

 Patellostium ottrayen.se,o Myalina ameiformis^' Seminida suMilita,^ and Euinetr'ta 

 vwosteri.j 



Of these citations the original material in most cases has come under my obser- 

 vation and is included in the discussion of species and of faunal evidence. The 

 originals of Loplwi^hyllum profundum var. saurideiu^ Cleiothyrls oriicidaris. and 

 Seminula suhtilita, however, have not come to hand. The two latter I have recog- 

 nized in Colorado, though not from the localit}^ of original citation. Lophophylhmi 

 profundum also I have cited from the State, though not the variety sauridens, which 

 may, however, be included in the material referred to the central form. 



aAs BcUerophon suVpapiUoszis from northwestern Colorado. White, U. S. Geol. Geog. Surv. Terr., Twelfth Ann. 

 Kept., for 1S78, pt. 1, 1880, p. 138, pi. 34, fig. 3a. 



i As Plllodkti/a Inangidata from Yampa Plateaa, northwestern Colorado. White, op. cit., p. 131, pi. 33, figs. 3a-e. 



cAs Lf>phopki/Uum.prol//ci-dm var. sauridens from Rock Creek, Lake County, Colo, White, U. S. Geog. Geol. Surv. 

 W. 100th Jler., Kept., vol. 4, 1877, p. 101, pi, 6, figs. 4a-d. 



<i As Froductus muricatJis iTom Rock Creek, Lake County, Colo. White, U. S. Geog. Geol. Surv. W. 100th Mer., Kept., 

 vol. 4, 1877, p. 120, pi. 8, figs. 4a-c. 



p.^s Spln'f/era 2ilci'iosidcata from Rush (probably misprint for Rock) Creek. Lake County, Colo. White, U. S. Geog. 

 Geol. Surv. W. 100th Mer., Rept., vol. 4, 1877, p. 143. pi. 10, flgs. 5a-d. 



f As Plearotouiaria faggarU from near Horseshoe Mountain, South Park, Colorado. Meek, U. S. Geol. Geog. Surv. 

 Terr., [Seventh] Ann. Rept., for 1873, 1874, p. 231. 



a As BcUerophon ourayensis from Ouray, Colo. Gurley, New Carb. Fos.s., Bull. No. 2. 1884, p. .s. 



'1 From Ouray, Colo. Gurley, New Carb. Foss., Bull. No, 1, 1881, p. 4. 



'As Atliyris subtilita from the Sierra la Plata. Newberry, U. S. Expl. Exped. from Santa Fe to Grand and Green 

 rivers, 1876, p. 138. 



J As Sctsia woosteri from 18 miles north of Greeley. White, U. S. Geol. Geog. Surv Terr.. Bull., vol. a, 1879, p. 21:"i. 



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