NON-MARINE FOSSILS OF THE MONTANA. 



153 



limited to an undetermined Unto, a Melania, Valvaia nana, and Physa' 

 carletoni at Coalville, and the somewhat doubtful occurrence of Campe- 

 loma vetula at Point of Rocks. In addition two Laramie species of Melania 

 are found near Point of Rocks, but associated with marine and brackish- 

 water shells. 



Brackish-water forms are more abundant and are mostly of types that 

 persist throughout the upper Cretaceous. Some of the same species 

 occur in the Laramie. At Coalville there is a larger proportion of local 

 species associated with the plants, and with them there are a few that 

 belong to marine genera. The following species, in addition to the fresh- 

 water forms already noted, have been collected there from the same 

 horizon : 



Ostrea coalvillensis, Meek. 



Anomia propatoris, White. 



Modiola multilinigera, Meek (?). 



Cyrena carletoni, Meek. 



Corbicula sp. 



Avicula sp. 



Corbula subtrigonaUs, M. and H. 



Turritella spironema, Meek. 

 Neritina bellatula, Meek. 

 Neritina carditoides, Meek. 

 Neritina bannisteri, Meek. 

 Eulimella (?) chrysaliis, Meek. 

 Eulimella (?) inconspicua, Meek. 



From the neighborhood of Point of Rocks the following species have 

 been obtained : 



Ostrea glabra, M. and H. 

 Ostrea glabra, var. ivyomingensis, Meek. 

 Anomia gryphorynchus, Meek. 

 Corbicula cytheriformis, M. and H. 



Corbicula occidentals, M. and H. 

 Odontobasis buccinoides, White. 

 Pectunculus holmesianus, (White 



The last two species of the list belong to marine genera, though they 

 are associated in the same layers with others which may live in either 

 marine or brackish waters. Two other marine species, Nuculana inclara, 

 (White), and Odontobasis (?) formosa, White, that have been described as 

 coming from the Laramie of northwestern Colorado, are most probably 

 also from a lower horizon, so that no strictly marine species are left in 

 the Laramie fauna. 



FOSSIL PLANTS OF THE MONTANA FORMATION. 



The following is a complete list* of the fossil plants which have been 

 found at Point of Rocks below the marine Cretaceous : 



* The species marked with a * are confined to these beds, while those marked with a t are open 

 to question either as to their identification in the Point of Rocks beds or at the other localities 

 from which they have been reported. Only the unmarked species have an unquestioned distribu- 

 tion outside of the Point of Rocks beds. 



