244 ' EEPOET UNITED STATES GEOLOGICAL SURVEY. 



18. Bulinus disjunctus White. 



This species is described in a foot-note on page 170 of this report. It 

 has been found in the Laramie beds of the valley of Crow Creek, Eastern 

 Colorado, and in the upper beds at the coal-mines near Evanston, Wyo., 

 there is a form which is probably specifically identical with it. 



19. MaGrocyclis spatiosa Meek & Hay den? 



A species evidently referable to this genus, and, so far as the somewhat 

 imj)erfect examples will admit of comparison, seems to be identical with M. 

 spatiosa., was found in the upper beds at the Evanston coal-mines. This 

 species is described and figured by Mr. Meek in vol. ix, U. S. Geol. Sur. 

 Terr., and is there referred to the Wind Eiver Group. Overlooking this 

 fact, but following a general label found accomi^anying a tray of Upper 

 Missouri fossils, among which were the types of both this species and 

 Columna teres Meek & Hay den, I referred them both to the Judith 

 Eiver Groui) in the table on page 722, Bull. U. S. Geol. and Geog. Sur. 

 Terr. vol. iv. Concerning the Columna., the error, if it be one, amounts 

 to but little, as it is now well known that several species of fossils which 

 respectively characterize the Judith Eiver and Fort Union beds, are 

 associated together in the same strata of the Laramie Groui) elsewhere. 

 As to the MacrocycUs I can at present only say that the examples which 

 I obtained from the Upper Laramie beds at the Evanston coal-mines in 

 Bear Eiver Valley answer well to the description and figures of 3£. spati- 

 osa given by Mr. Meek. It is true my exami)les are not perfect, and it 

 may be that when better ones are found they wiU show specific differ- 

 ences from the types of M. spatiosa. 



20. Selix evanstonensis White. 



This species was found in the upper beds at the Evanston coal-mines, 

 and is described in Bull. U. S. Geol. and Geog. Sur. Terr. vol. iv, p. 714, 

 where the mention of its locality was inadvertently omitted. 



21. Columna teres Meek & Hayden. 



So far as the specimens will admit of comparison this species appears 

 to be identical with C. teres from the Fort Union beds of the Upper Mis- 

 souri Eiver region, the type of which is figured in vol. ix U. S. Geol. 

 Sur. Terr. (See remarks under l^o. 19.) 



22. Neritina naticiformis White. 



This small shell was found quite plentifally in certain of the clayey 

 layers of the lower beds near Mellis Station, but it has not been discov- 

 ered elsewhere. It is described in Bull. U. S. Geol. and Geog. Sur. Ter., 

 vol. iv, p. 715. 



23. Goniohasis arcta Meek. 



Associated with I^Tos. 13 and 22 and other species in the lower beds 

 near Mellis Station numerous examples have been found which answer to 

 the figure and description of G. arcta as given by Meek in U. S. Expl. 

 Great Basin of Utah (Simpson). The locality is there given as " Ham's 

 Fork," but this reference is probably an error, as was that of its associ- 

 ate (Ko. 13 I/imncea {Limnopliysa) nitidula), as shown by Mr. Meek in U. 

 S. Geol. Sur. 40th Parallel, vol. iv, p. 182. 



24. Goniohasis clehurni White. 



This, together with the two following species, which have been found 

 only in the lower beds of the Bear Eiver Group in Bear Eiver Valley, 

 forjns a natural group, which might properly be regarded as a section 



