The Crawfishes. 235 
From numerous observations of the crawfishes of the lake the fol- 
lowing conclusion may be drawn: 
There appears to be no special time for mating, and no special breed- 
ing period was observed; nor again, any special time for moulting. It 
is probable that in the fairly uniform temperature of the lake the lives 
of the crawfishes are not so markedly divided into seasons as they are 
in the river crawfishes. Generally, in rivers heavily populated with 
crawfishes, one can find immense numbers of moulted shells at certain 
periods—usually about the beginning of July—but in Lake Maxinkuckee 
only occasional and scattered cast-off skins can be found. 
The nature of the food was not easily discovered by examination of 
stomach contents, as the material was too finely comminuted. A few 
were seen eating dead fishes as mentioned above. They are usually 
found in the vicinity of minnow nests, and probably devour fish eggs 
to some extent. Various fishes, especially walleye and bass, eat them 
at times, and they are one of the principal foods of the soft-shelled 
turtle. The lake species are rarely used for bait, perhaps because of 
the difficulty of obtaining soft-shells or ‘“‘peelers” in the lake; river 
crawfishes are sometimes used. 
The crawfishes of the lake often have protozoa attached to the gills, 
but this probably does not seriously inconvenience them. 
4. Cambarus immunis spinirostris Faxon. The Rock Crawfish. 
In general form and appearance this species is somewhat like the 
last, but it lacks the longitudinal ridge on the rostrum. The teeth of 
the rostrum are apt to be very small and, in the males, the tips of the 
first abdominal appendages are slender, blade-like, and recurved. 
Represented in the collections by nine males and eight females from 
Aubeenaubee Creek, one male from Culver Inlet, and twelve young 
females from Norris Inlet. 
