226 REPORT UNITED STATES GEOLOGICAL SURVEY. 



LIST OF FOSSILS OF THE WASATCH GROUP COLLECTED IN WHITE 

 RIVER VALLEY, COLORADO. 



1. Unio slioslionensis Wliite. 



2. Unio washalciensis Meek. 



3. Physa pleromatis White. 



4. Goniohasis tenera Hall. 



5. Viviparus paludinwformis Hall. 



NOTES ON THE WASATCH FOSSILS OF WHITE RIVER VALLEY. 



1. Unio slioslionensis White. 



This species is described in Powell's Eeport on the Geology of the 

 Uinta Mountains, p. 126, the types having been collected from differ- 

 ent portions of the Green Eiver Group in Southern Wyoming. Not only 

 this, but also all the other species of the foregoing list, excex^t Physa ple- 

 romatis, are known to range from the Wasatch Grouj) into, and part of 

 them entirely through, the Green Eiver Group. 



2. Unio tvashalciensis Meek. 



Mr. Meek described this species in the Ann. Eep. IT. S. Geol. Sur. 

 Terr, for 1870, p. 314. It is quite a common species in both the Wasatch 

 and Green Eiver Groups, but it is seldom, if ever, found well preserved. 

 Among typical examples of this species were found some that are at 

 least one-third larger than Mr. Meek's types. Being only in the con- 

 dition of casts, their specific determination was not satisfactory, and it 

 is possible they represent a new species. 



. 3. Physa pleromatis White. 



This species is described and figured in a^oI. iv, Expl. and Sur. West 

 of the 100th Meridian, the types having been collected at Last Bluff, 

 Utah. It is not an uncommon species in the Wasatch Group in Utah^ 

 Wyoming, and Colorado. An example found in White Eiver Valley is 

 remarkably large, fully double the size of the tyjie, and the largest ex- 



. ample of the genus known to me. 

 4. Goniohasis tenera Hall sp. 



In Fremont's Eeport on Oregon and J^Torth California, 1845, Professor 

 Hall described and figured Cerithium tenerum and G. noihdosum, both of 

 which, without doubt, belong to the geims Goniohasis, and both are doubt- 

 less of the same species. G. tenera being the first in order of description 

 in that rej^ort, that name is used as the proper name of the species. In 

 Proc. Acad. Nat. Sci. Philad. 1860, Meek described a form from Wyo- 

 ming under the name of Melania simpsoni; and in the Am. Jour. Conch. 

 1868, Conrad described another, from Wyoming, under the name of G. 



- carteri, both of which are other synonyms of G. tenera. In the An. Eep. 

 U, S. Geol. Sur. Terr, for 1870, Meek changed G. nodidosum Hall sp, to G. 



. nodulifera, because the former name was preoccupied by Lea for a recent 



; species. This was unnecessary, because both are other synonyms of 

 G. tenera. Several distinct species of Goniohasis are known to exist 

 in the Laramie Group, but so far as I am able to discern, only one 



. species of that genus has yet been collected from either of the three 

 great fresh water deposits of the west, namely, the Washakie, Green 

 Eiver, and Bridger Groups. This species is subject to great inter-specific 

 variation, and is known to range through the greater part of the Wasatch 



^ Group ; through the Green Eiver Grou^) ; and is beheved to range well 



; up into the Bridger Group also. It has even a greater variation than is 

 .indicated by the fact that it has already received three specific names, 

 • Jbecause a variety M'hich I collected at Tabor Mountain in Southern Wyo- 



