PARASITES 153 
way to his lodge was lying dead by his burden. Many of 
them which I opened were red and bloody about the heart. 
Those in large rivers and running waters suffered less; al- 
most all of those which lived in ponds and stagnant waters 
died. Since that year the beaver have never been as plenti- 
ful in the country of Red River and Hudson Bay as they 
used to be.’”’ 
None of the other authors whom I have consulted have 
anything to say about disease of the beaver. 
PARASITES 
Beavers are afflicted, like most other mammals, with 
parasites, but these appear to be unique in that they belong 
to the order Coleoptera, which is that to which all beetles 
belong, not to the Mallophaga, which includes the biting 
lice of mammals and birds. 
Platypsyllus castoris is the name given to the better known 
of these parasites, and it has been found on both American 
and European beavers. It has been recorded from Alaska, 
Colorado, Dakota, Texas, Nebraska and California ‘n 
America. Riley (Castorologia, Appendix C, p. 238) says 
that Leptinillus validus Horn, is an associate parasite of 
Platypsyllus on the beaver, a number of both having been 
taken from beaver skins brought from Alaska. 
Prof. T. D. A. Cockerell writes me that this is all that is 
known of its habits. L. testaceus occurs in nests of bumble- 
bees and field mice. LL. aplodontia was found in California 
on Aplodontia, or mountain beaver, a mammal whose habits 
are very different from the real beaver. 
Vernon Bailey says that two specimens of L. validus were 
the only parasites found on four old beavers taken for 
specimens in Wisconsin. None was found on six young 
beavers kept in captivity. 
