136 THE NAUTILUS. 



writer's notes which follow. Kirkland says,' "This is a deep 

 water species, which migrates shoreward in the fall, doubtless 

 for spawning purposes, as adults only have been captured, but 

 this should be verified by dissection. September 25 is the 

 earliest date they have been taken, and they remain until ice 

 forms, how much longer is not known." Sargent * reports them 

 in Heath Lake, Minnesota, in the fall, and adds, "Where do 

 they keep themselves in the summer? ", 



This question can now in a measure be answered as the 

 species has been found in July in Lower South Bay, Oneida 

 Lake, in several localities. The specimens collected were all 

 young, none exceeding 11 mm, in length, the greater number 

 being 3 to 5 mm. long. They were invariably found on the 

 leaves or stem of the pond-weed (Potamogeton interruiptus) . It 

 is evident that they do not retire to very deep water but only 

 to the zone where this pondweed, or perhaps other suitable 

 vegetation grows. This may be in water from two to six feet 

 deep. The shells are very difificult to find, as in life they are 

 nearly the color of the plant and look exactly like a young leaf 

 beginning growth. This plant is admirably adapted for the use 

 of this snail, its leaves being very long and exceedingly narrow 

 and flat. Five specimens gave the following measurements: 



Whorls 2; length 3.0; breadth ,6; aperture length 1.5; 

 breadth .5 mm. 



Whorls 2^; length 4.0; breadth 1.0; aperture length 2.0; 

 breadth .75 mm. 



Whorls 2^ ; length 5.5; breadth 1.4; aperture length 2.0; 

 breadth 1.0 mm. 



Whorls 3 ; length 8.0 ; breadth 1.7 ; aperture length 3.5 ; 

 breadth 1.0 mm. 



Whorls 3:^ ; length 10.5 ; breadth 2.5 ; aperture length 5.0 ; 

 breadth 1.5 mm. 



The whorls are usually flat-sided as in the adult shell, but 

 in two specimens they were somewhat rounded. Adult speci- 

 mens from Nicholson's Bay, Oneida Lake, measure : 



* Baker, Lymnaeidae of North and Middle America, page 197, 1911. 

 'Nautilus, IX, page 127, 1896. 



