LYMNiEID^E OF NORTH AMERICA. 311 



Quebec: Saxicava Sand, Packenham Mills, 266 feet above Lake St. Peter, 

 St. Lawrence Valley (Dawson. Probably drifted into sea by fresh-water 

 streams) . 



Ecology: Found plentifully in bodies of water of greater or less 

 size, on floating sticks and submerged vegetation, on stones and on 

 the muddy bottom. Inhabits both clear and stagnant water, but pre- 

 fers a habitat in which the water is not in motion. Seldom found 

 out of the water, as is the case with the smaller species of the sub- 

 genus Galba. The more distinctly malleated forms inhabit stagnant 

 pools where the bottom is muddy, with more or less decaying vege- 

 tation present. The food of palustris is made up of both animal and 

 vegetable matter, the species being literally vegetiferous, scavengif erous 

 and carnivorous. The writer has noted it feeding upon the dead car- 

 casses of dogs, cats, rats, etc., upon rotting vegetables and decaying 

 fruit. Dr. Sterki (Nautilus V, p. 94) has seen it in the act of eating 

 a living leech. The animal of palustris is very rapid in movement. 

 When crawling, the shell is frequently moved rapidly from side to 

 side, and is carried at all conceivable angles. It is a very rapid feeder 

 and will soon clear up the sides of an aquarium. Like other species 

 of the genus, palustris has the habit of rising very suddenly from the 

 bottom to the top of the water, where it will then float, shell downward. 

 (Baker.) 



"In small brook on farm near Caribou Village, Maine." (Ny- 

 lander.) 



"L. palustris I have found only in lakes except some unusually 

 large specimens from a small ditch connecting two lakes on the plains 

 near Fort Collins, and found none in either of the lakes, but it was 

 when the lakes were full, at which time it is usually harder to find 

 Mollusca along the shores of our fluctuating lakes. In the valleys I 

 have found them in lakes containing some vegetation but not choked 

 therewith except around the inlets. In the mountains I have found 

 them only in sedge-choked, very shallow lakes which nearly dry up 

 in the late summer. At Lake George, altitude about 8000 feet, I found 

 it in very shallow water with fine mud bottom at the head of the lake, 

 and in a seepage pool with fine mud bottom just below the lake. This 

 lake is purely artificial, formed by throwing a dam across the South 

 Platte at a point where the canyon widens out into a broad valley, 

 so I presume these shells may have been brought down the river from 

 some lake nearer its source. There is no vegetation in either the lake 

 or the pool. It is interesting to note that the Lymnasas occupied the 

 same region in Tertiary time (L. sieverti, L. scudderi, Ckll., Bull. Am. 

 Mus. Nat. Hist., Vol. 22, p. 461), but the lake in which they lived 



