THE NATURAL HISTORY SURVEY. 



275 



but never twice as long, as in reflexa. The malleation is usually, 

 though not always, present. There seem to be no geographic 

 races to this form, as several varieties may be found in a 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 Limnceids is supposed to be exclusively 



Fig. 89. 



Radula of LIMN.EA 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 



FIG. 90. 



First lateral tooth of LIMN^EA 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. The species is found in almost all 

 parts of the area and in some localities is the predominating 

 form. 



