134 STANTON & KNOWLTON — LARAMIE AND RELATED FORMATIONS. 



opposite the last-mentioned locality there is a bed, composed of immense 

 numbers of fresh-water shells, from which the following were collected : 



Spheerium sp. 



Tulotoma thomsoni, White. 



Campeloma multilineata, M. and H. 



Unio dame, M. and H. 



Unio brachyopisthus, White. 



Unio holmesianus, White. 



Unio (seven undescribed species, part of 

 which are represented at other locali- 

 ties). 



Again, on very near the same horizon as the last, on the north bank of 

 Lightning creek, near its mouth, a small collection was made as follows : 



Unio danx, M. and H. 

 Anodonla parallela, White. 

 Campeloma midtdineata, M. and H. 



Campeloma producta, White. 



Tulotoma thompsoni, White. 



Physa copei, var. canadensis, Whiteaves. 



The fossils of the above lists clearly all belong to one fresh-water fauna, 

 which in this region has its greatest development in the upper 400 or 500 

 feet of the Ceratops beds. No fresh-water invertebrates have been found 

 in the underlying several hundred feet of presumably fresh-water beds, 

 and they are not abundant in those above the horizons above mentioned, 

 but the few species that have been collected do not include any addi- 

 tional forms. On Lightning creek, a short distance west of the western 

 limit of Ceratops beds, as given by Hatcher, and consequently overlying 

 them, Unio couesi, White, occurs, and higher up in the same bluff Cam- 

 peloma multUineata, M. and H., is abundant. Near the latter horizon a 

 considerable collection of plants belonging to the Fort Union flora was 

 obtained, including the following species : 



Equisetum sp. 



Anemia. 



Sequoia nordenskioldi, Heer. 



Sequoia, sp. (?) 



Thuja, n. sp. 



Salix sp. 



Viburnum crenalum (?), Newberry 



Viburnum, n. sp. 



Viburnum, fruits of. 



Cornus acuminata (?), Newberry. 

 Grewia celastrinoides, Ward. 

 Grewia crenata, (Ung.) Heer. 

 Celastrus curvinervis, Ward. 

 Celaslrus pterospermoides, Ward. 

 Zizyphus serrulatus, Ward. 

 Zizyphus sp. 

 Vitis cuspidala, Ward. 

 Diospyrus brachysepala, Al. Br. 



This list embraces 18 species, of which number at least 10 are species 

 before described and which can be employed in determining the age. 

 Nine of the 10 species are confined to the Fort Union group, the remain- 

 ing species, Diospyros brachysepala, having a wide distribution, including 

 Golden, Sand creek, and Sedalia, Colorado ; Black Buttes, Point of Rocks, 

 Hodges pass, and Green river, Wyoming, and Fort Union, Montana. 

 There seems, therefore, no doubt as to the correctness of referring this 



