242 REPORT UNITED STATES GEOLOGICAL SURVEY. 



30. Yiviparus coucsi White. 



31. Campcloma macros}) ir a Meek. 



32. Spirorbis t 



33. Cijpris % 



34. Cycloid fish-scales. 



35. Nutlets of Chara. 



NOTES ON THE LARAMIE FOSSILS OF BEAR RIVER VALLEY, WYOMING. 



1. Membranipora ? 



Some fragments of a Polyzoan were found incrusting the surface of 

 Corbula piriformis and other shells of the lower beds, which are appar- 

 ently of the same species as those found on the oyster-shells at Point of 

 Bocks, mentioned on a former page. They are too imperfect for satis- 

 factory classification, but are of some value as additional evidence of at 

 least some degree of saltness of the water in which the associated mol- 

 lusks lived. 



2. Ostrea ? 



A few separate valves of an undetermined species of Ostrea were found 

 here and there in the lower beds ; and in some places a thin layer was 

 found mainly composed of them. They are all comparatively small 

 shells, and all seem to have been somewhat waterworn before being 

 finally imbedded. 



3. Volsella » 



A couple of fragments only of a small undetermined species of this 

 genus were found near Mellis Station. 



4. Unio vetustus Meek. 



Shells of this species are quite abundant in the lower beds, a large 

 proportion of which have both valves unseparated. It is figured and 

 described in vol. iv, U. S. Geol. Sur. 40th Parallel, and also in U. S. Expl. 

 Great Basin of Utah (Simpson). 



5. Unio belliplicatus Meek. 



This species is found associated with ~No. 4 and in similar condition ; 

 but it is not quite so abundant. It is figured and described in vol. iv, 

 TJ. S. Geol. Sur. 40th Parallel. This species is an interesting one because 

 of the fact that its style of surface ornamentation is different from that 

 of any other known North American species, either fossil or recent. 



6. Pisidium saginatum White. 



Only three or four examples of this species were discovered, and these 

 only at the Evanston coal-mines, in the upper Laramie beds there. 



7. Sphcerium 1 



A few casts only of a small species of this genus were found associated 

 with numerous other small fresh -water shells in a gray clayey layer, 

 about 40 feet above the principal bed of coal at the Evanston mines. 



8. Corbicula ( Veloritina) durlceei Meek. 



A large number of examples of this species exist in the lower beds 

 wherever they have been exposed. It is the type of Meek's subgenus 

 Veloritina, and is described and figured by him in vol. iv, U. S. Geol. 

 Sur. 40th Parallel. Among the collections made by Lieutenant Wheeler's 

 parties in the valley of Virgen Biver, Southern Utah. I identified this 

 species, and figured and described it in vol. iv, U. S. Expl. and Sur. 

 West of the 100th Merid. 



