82 Psyche [April 
to make its classification accord with that which has been proposed 
for some of the other orders of insects, but owing to the cormpact nature 
of the group he has been compelled to select slight, single characters, 
and each superfamily differs from the one preceding it by the loss of 
one tarsal joint in the male. Similarly the eight families are segre- 
gated by the number of joints and forin of the flabella of the antennae. 
Due to the extremely degenerate form of the females, still less evident 
characters are available for their classification. It seems unfortunate 
that such a very ambitious and cumbrous grouping should have been 
adopted for it can hardly fail to confuse the student who is not a 
specialist in the order, and to make it appear out of its proper pro- 
portion in the taxonomy of insects in general. 
103 species are listed and described, belonging to 37 genera, 24 of 
which are monotypical, while 45 or nearly half the species belong to 
two genera. 69 of the species, all but 7 of which are from North 
America, are described as new. Many of the species known from only 
females or single specimens appear to be very closely related, and 
Pierce assumes that each parasite species can be defined by its host 
species. ‘Time only can tell whether such a supposition is correct, 
but the more definite knowledge which we have concerning other 
parasitic insects shows that such generalizations should not be made too 
hastily, especially when they relate to the genera of hosts and parasites. 
A case of such association is the genus Homilops where species known 
only by females are segregated with one kn»wn only by the male on 
account of their hosts being congeneric. 
In addition to many figures, there are full descriptions of all new 
species, and collected literature relating to all exotic ones, as well as a 
very complete compendium of the known facts regarding the develop- 
ment, anatomy, and ethology of the group. This will form a splendid 
basis for future work, which it is to be hoped will be undertaken by 
many entomologists. 
A very extensive bibliography of fifteen pages completes the paper. 
Some of the references will appear superfluous to working naturalists, 
however, such as yearly citations of the Zoological Record, and the 
Zoologischer Anzeiger, and the inclusion of the Century Dictionary. 
C. Ty Brows 
