LYMNZIDZ OF NORTH AMERICA. 197 
BRITISH AMERICA, 
OnTARIO: Ottawa, Carleton Dist. (Heron); Hamilton, Wentworth Dist. 
(Walton). ; 
GEOLOGICAL, DistRIBUTION: Unknown. 
Ecotocy: But few collectors have studied the habitat relations 
of this beautiful species and the writer takes great pleasure in quoting 
the following account by Dr. Reynold J. Kirkland, of Grand Rapids, 
Michigan : 
“On Thanksgiving Day, 1897, a collecting trip to Reed’s Lake 
was made. The day was bright, cold and windless; the surface of the 
water covered with a thin sheet of ice, not thick enough to greatly 
interfere with wading. My quest was particularly for Pisidia. On 
clearing my scoop, while standing in about two feet of water, I was 
greatly surprised to find two examples of L. gracilis amongst the lit- 
_tle bivalves at the bottom. They had evidently been dislodged from 
the rushes and had fallen into the scoop as it was being brought to 
the surface. Further search for Pisidia was abandoned, and the fol- 
lowing several hours were spent in sweeping the rushes with my scoop. 
The result was over eighty specimens of this exquisite mollusk, a fine 
sauce for the cold turkey that awaited my return home at dark. 
“Each fall save one since then, from one to a dozen trips have been 
made to this spot, with varying success. One year four trips yielded 
but five individuals; while a single visit another year resulted in a bag 
of nearly two hundred. 
“This is a deep water species, which migrates shoreward in the 
fall, doubtless for spawning purposes, as adults only have been cap- 
tured, but this should be verified by dissection. September 25th is the 
earliest date they have been taken, and they remain until ice forms, 
how much longer is not known. They are gregarious, or at least live 
in colonies. This colony has occupied an area of not more than a 
few square rods any one year; and the location of this area has not 
varied a hundred feet in either direction during the ten years of its 
observation. Rushes grow along about two miles of the shore line 
of this lake. Systematic examination of perhaps a half mile of this 
distance has failed to disclose another colony. The home of this mol- 
lusk is on the rushes or reeds common to all our inland waters; in 
water from one to three feet deep; and invariably from six to eight 
inches from the bottom, on the side of the reed facing deep water, the 
apex of the shell pointing downwards,—though in a few instances the 
apex has been upwards, as if in the act of descending. Incidentally, 
it may be remarked that Ancylus fuscus is abundant on these same 
