THE NAUTILUS. 103 



Volutomitra alaskana n. sp. 



Shell fusiform, with about six moderately convex whorls; suture 

 distinct, surface wholly minutely spirally striated, covered with an 

 olivaceous periostracum over a white or yellowish shell ; aperture 

 longer than half the total length, with a rather wide canal, callous 

 pillar and body in the adult, and simple outer lip ; the canal has a 

 well marked siphonal fasciole, and is slightly flexuous ; plaits nor- 

 mally four, rarely three or five, strong and rather distant ; nucleus 

 almost always eroded; Ion. 44, diam. 17.5 ; Ion. of aperture, 26 mm. 



Habitat in the southern and eastern parts of Bering Sea and the 

 Aleutians, in 60 to 85 fathoms, muddy bottom, and southward in 

 constantly deeper water, following the temperature of 39° Fahr. to a 

 point off San Diego, California, in 822 fathoms. 



This species differs from V. gronlandica in its much greater size, 

 less rufous color, and pervasive fine spiral sculpture, but otherwise is 

 very similar. It was first dredged by the writer in the eastern Aleu- 

 tians, and has since been obtained by the U. S. Fish Commission. 

 The Atlantic species is usually about 18, but reaches 27 mm. in 

 length, and is smooth above, with a few coarse spiral stria? on the base. 



COLLECTING SHELLS IN MONTANA. 



BY MOKTON J. ELROP, UNIV. OF MONTANA. 



[Continued from page S9.~\ 

 Sphcerium partumeium Say. 



This beautiful shell is common in the ponds near Flathead Lake 

 and around Missoula. They live in the dense vegetation, in com- 

 pany with Planorbis trivolvis, larvae of Odonata, Cyclops, Daphnia, 

 and numerous water insects. They arc gathered by pulling out a 

 mass of the vegetation, picking it to pieces, and here and there find- 

 ing the delicate shells. A single dead shell was found on the beach 

 of Swan lake. None have been discovered in the small cold water 

 lakes in the Mission mountains. 

 Planorbis trivolvis Say. 



This cosmopolitan species is the most abundant thus far found, 

 and has been taken in most of the ponds where shells are found. It 

 has been taken around Missoula in the streams, in the lakes of the 



