1919.] NATURAL SCIENCES OF PHILADELPHIA. 195 



mollusca of glacier national park, montana. 



by s. stillman berry. 

 Introduction. 



During the month of August, 1916, in the course of a brief vaca- 

 tion in the Glacier National Park, Montana, the writer incidentally 

 made a small collection of mollusks, which, though doubtless not 

 in any way complete for even those portions of the region visited, 

 is none the less of considerable interest, particularly from the 

 standpoint of the zoogeographer. The facts, that within the bound- 

 aries of this Park the three principal continental watersheds find 

 their point of junction, and that collections were made on all three 

 sides of the continental pinnacle thus formed, give a peculiar interest 

 to the records. To the great, rough, triangular rock called Triple 

 Divide Peak, belongs the honor of being, at least so far as drainage 

 goes, the top of the North American Continent. One of its three 

 faces drains into Norris and Red Eagle Creeks, and thence via the 

 St. Mary's and Saskatchewan Rivers into Hudson's Bay; one drains 

 into Cut Bank Creek and thence \ia the Marias River and the 

 Missouri-Mississippi into the Gulf of Mexico; the third drains via 

 Nyack Creek and the Flathead and Columbia Rivers into the Pacific. 



This will suffice to indicate why the student of geographical dis- 

 tribution must find a peculiar interest in the elucidation of the fauna 

 of the region, though unfortunately the present collections are not 

 sufficiently complete that any very general conclusions may be safely 

 drawn, even for the single phylum Mollusca. They were carried 

 out at odd moments along the trail or while stopping to rest, and 

 nowhere was it possible to make them reasonably exhaustive. 



The writer was accompanied on the entire expedition by Mr. 

 Elw^n H. Dole, of Winnecook, Montana, and during the latter 

 part of the tramp by Dr. A. H. Warthin, of the University of 

 JVIichigan, and his son, Master Aldred Warthin. His thanks are 

 due to each of these gentlemen for help in the work of collecting, 

 as well as to Mr. E. G. Vanatta, of The Academy of Natural 

 Sciences of Philadelphia, for his critical comparison of certain 

 specimens with others in the collections of the Academy^ 



The total number of species taken was not large — some eleven 

 of land snails and a single freshwater bivalve — but several con- 



