232 Proceedings of Indiana Academy of Science. 
THE CRAWFISHES. 
By WILLIAM PERRY Hay, Head of the Department of Biology and 
Chemistry, Washington, D. C., High Schools. 
Crawfishes are quite common in Lake Maxinkuckee and in Lost Lake; 
on the land about the lakes they are less frequent. The truly aquatic 
species are found chiefly in the shallower depths, hiding under rocks, 
sticks, and among Chara and other aquatic vegetation. But even at 
their best, not as many will be taken in the seine as will be secured in 
similar collecting in sluggish streams. The greatest number taken in 
one haul of the seine in Lake Maxinkuckee was twenty-two. 
In the collections turned over to me for identification and study, 
four species are represented, namely: Cambarus blandingi acutus, C. 
diogenes, C. propinquus, and C. immunis spinirostris; or, using English 
names instead of Latin combinations, we may designate these four spe- 
cies as the Pond Crawfish, the Solitary Crawfish, the Gray Rock Craw- 
fish, and the Rock Crawfish. Of these, the first three have long been 
known to occur in northern Indiana, but C. immunis spinirostris has 
not heretofore been known north of Terre Haute. One or two other 
species probably occur in the Maxinkuckee region. C. argillicola Faxon 
has been reported from several localities north, east and south of Lake 
Maxinkuckee, and C. rusticus Hagen has been taken near Mount Etna, 
Huntington County, Indiana. 
Beyond doubt, the crawfish fauna of this lake, or of any other, will 
repay careful study. The habits and economic importance of these 
animals are only poorly known; but it must be that, as a source of food 
supply for other animals, or as scavengers, they fill a field of usefulness. 
As the species of crawfishes are rather difficult to distinguish, and 
as the present account is for the general public rather than for the 
zoologist, it will be impracticable to give more concerning the structural 
characters of these than is absolutely indispensable for their recogni- 
tion. Before beginning this, however, it must be stated that the male 
crawfish may be distinguished from the female by the presence of two 
pairs of rigid appendages which are attached to the first two joints of 
the abdomen or tail, and which, projecting nearly straight forward, lie 
in a sort of groove between the bases of the walking legs. In the female 
the abdomen is broader than in the male, and the appendages of the 
first two joints are slender and flexible like those which follow. The 
rostrum is the beak-like projection of the shell (or carapace) above 
the eyes. 
