1929] 
Habits of Amphizoa 
385 
certain Hydrophilidse. Indeed one hydrophilid, Hydrobius 
scabrosus Horn, is often found with Amphizoa, which it 
evidently imitates in its method of life. The Hydrobius is 
sometimes found along lake shores, however. 
Amphizoa emits an odor which is rather pleasant, at least 
to the collector, and which Horn compares to that of decay- 
ing wood. The beetles also exude a thickish, yellow fluid 
from the joints, so that they leave a cigarette-like stain on 
the fingers. 
Dr. Van Dyke’s classification of our three American 
species (Pan-Pacific Entomologist 3, 1927, p. 197) is per- 
fectly satisfactory. D. striata and D. lecontei hardly differ 
in color, however, as my large and variable series show, and 
the size difference is slight. The important difference is, of 
course, in the form of the elytra. It will be interesting to 
see whether the two species occur together, or whether in- 
termediate forms occupy intermediate regions. 
