NOTES ON THE HABITS OF CAMBARUS 
IMMUNIS HAGEN. 
J. ARTHUR HARRIS. 
In the present notes I intend to give only a few observa- 
tions made on the habits of one of our common crawfishes, 
Cambarus immunis Hagen. The material which I have exam- 
ined seems quite variable, and a part of it would probably fall 
under Faxon's variety, spinirostris. It does not embrace all 
the data I have at hand, and as more is being collected as 
rapidly as opportunities for field work are presented, I hope in 
the near future to give a much more complete account of the 
habits of this and other forms. These few points are pre- 
sented here simply because they seem to throw some light 
upon one or two questions concerning the habits of the craw- 
fish, a field which I feel sure is deserving of careful study. 
C. immunis is decidedly a mud-loving species. Faxon! says : 
«Mr. H. G. Hubbard has found it in muddy pools and ditches 
connected with the Detroit River, Michigan. According to Mr. 
Hubbard, it does not form burrows but conceals itself among 
weeds." Herrick,? in his description of C. signifer [= C. immu- 
nis], says: “ Found by hundreds in a shallow pool known as 
Grass Lake in Richfield, Hen. County." Forbes? says: ** This 
is the commonest species of central Illinois. It is especially 
frequent in the muddy ponds of the prairies, whence it may be 
drawn by the hundred with a small seine." Hay * says: “ This 
species is a mud-lover, being found in great numbers in muddy 
1 Faxon, Walter. A Revision of the Asad Mem. Mus. Comp. Zool. Har- 
ame MdL watt x (1885), No. 4. 
Papers on the Crustacea of the Fresh Waters of Minnesota, 
die eu on d Geol. of Minn., 1882. 
3 Forbes, S. A. List of Illinois o with Descriptions of New Species, 
Bull. IH. Ww. Lab. of Nat. Hist., vol. i, 
W. P. The Crawfishes of the Suis of a Twentieth Ann. Rept. 
Ind. pud Survey, 1896. 
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