62 CALIFORNIA ACADEMY OF SCIENCES. 



The shells mentioned in these notes were collected be- 

 tween June 22d and August 4th, 1889, while making a 

 vacation trip on foot across the Sierra Nevada, from Co- 

 lumbia through the Hetch-Hetchy and the Yosemite val- 

 leys, to Tuolumne Meadows and Mono Lake. It must 

 be stated that the ground traversed was not all care- 

 fully searched for shells, the main objects of the trip be- 

 ing recreation and a sight of the sublime scenery of the 

 high Sierra. Collections were made only as the accom- 

 plishment of these objects permitted. 



The altitudes given by me were mainly determined 

 with a small aneroid barometer, and unless given with 

 exactness must be considered as only approximate, those 

 most accurate being from Whitney's Geological Survey. 



The route across the mountains ran nearly east, and 

 within 18 miles of latitude 38°, which parallel passes close 

 to Lake Eleanor and through Mono Lake. The summit 

 of Mono Pass is 10,765 feet altitude, but the chief collec- 

 tions were made near the two lakes mentioned, on the 

 opposite slopes, as shown by the table. The following 

 list describes more fully the localities and conditions in 

 which each species was found, with other facts of inter- 

 est: 



1. ViTRiNA PFEiFFERi Ncwcomb. This species, first 

 described from the east slope of the Sierra, occurs at 

 high elevations, or from 4,000 to 8,000 feet in this lati- 

 tude, and south to Fresno County; also from 7,500 to 

 10,800 feet in the Rocky Mountains, and toward the 

 north comes down to the sea level in Alaska. I found it 

 in 1885 near Quincy, Plumas County, at about 3,400 feet, 

 latitude 40°. It is also reported from Vancouver's Island. 



2. Hyalina ARBOREASay. These specimens approach 

 the variety breweri of Newcomb, but are much nearer 

 the typical Eastern form. It is one of the most widely 



