THE NATURAL HISTORY SURVEY. 275 
but never twice as long, as in vefexa. The malleation is usually, 
though not always, present. There seem to be no geographic 
races to this form, as several varieties may be found ina single 
small pool, as is the case near Bowmanville. The lip may be 
thin or thickened, without regard to size. Some forms are 
ornamented by numerous fine, incremental lines, much as in 
some land shells. 
The food of the Lzmneids is supposed to be exclusively 
Fig. 89. 
Radula of LIMNHA PALUSTRIS Miiller. (Original.) c, central tooth; 
1, first lateral; 7,seventh lateral: 12-13, intermediate teeth; 14, 15, 24, 26, 
30, marginal teeth, 
vegetable, but from some recent observations and from late 
notes of other naturalists it would seem that the group is car- 
niverous as well as scavengiferous. The writer has noted this 
species feeding upon dead carcasses (dogs, cats, etc.), and 
Fic. 90. 
First lateral tooth of LIMN#A PALUSTRIS Miiller, with bifid outer 
cusp. (Original.) 
Dr. Sterki (The Nautilus, Vol. V, p.94, 1891) has seen it in the 
act of eating a living leech. Thespecies is found in almost all 
parts of the area and in some localities is the predominating 
form. 
