542 



A. G. LEONARD 



WESTERN DAWSON COUNTY, MONTANA 



Onoclea sensibilis fossilis Newb. 

 Populus cuneata Newb. 

 Leguminosites arachioides Lesq. 

 Celastrus pterospermoides Ward. 

 Populus amblyrhyncha Ward. 

 Populus daphnogenoides Ward. 

 Populus arctica Heer (as identified 



by Lesquereux). 

 Populus smilacifolia Newb. 

 Populus nebrascensis Newb. 



Populus genatrix Newb. 

 Populus speciosa Ward. 

 Cocculus Haydenianus Ward. 

 Platanus Haydenii Newb. 

 Plantanus nobilis Newb. 

 Sequoia Nordenskioldii ? Heer. 

 Thuja interrupta Newb. 

 Glyptostrobus europaeus (Brongn.) 

 Heer. 



BASE OF THE FORT UNION IN SIGNAL BUTTE, FIVE MILES EAST OF MILES CITY, 



MONTANA 



Taxodium occidentale Newb. 

 Sequoia Nordenskioldii Heer ? 

 Glyptostrobus europaeus (Brongn.) 



Heer. 

 Populus ? sp. ? cf . genatrix Newb. 

 Populus, possibly P. acerifolia Newb. 

 Betula, sp. new? 

 Corylus rostrata Aiton. 



Corylus americana Walter. 



Planera. 



Hicoria antiquorum (Newb.) Knowl- 



ton. 

 Hicoria ? sp. new. 

 Celastrus ovatus Ward. 

 Sapindus grandifoliolus Ward. 



The Fort Union beds contain many fresh- water shells, among 

 which the following species were collected: 1 



NORTHERN BILLINGS COUNTY, NORTH DAKOTA 



Campeloma producta White. 

 Viviparus retusus. 

 Viviparus leai M. & H. 

 Campeloma multilineata M. & H. 

 Thaumastus limnaeiformis M. & H. 

 Corbula mactriformis M. & H. 



Viviparus trochiformis M. & H. 

 Sphaerium formosum M. & H. 

 Bulinus longiusculus M. & H. 

 Micropyrgus minutulus M. & H. 

 Hydrobia. 



SOUTHERN BILLINGS COUNTY, NORTH DAKOTA 



Unio priscus M. & H. 



NORTHEASTERN CORNER OF MORTON COUNTY, 350 FEET ABOVE MISSOURI RIVER 



Corbula mactriformis M. & H. Viviparus trochiformis M. & H. 



Campeloma multilineata M. & H. 



1 Identified by Dr. T. W. Stanton. 



