142 
Psyche 
[December 
desired, and it is only with some doubt that the New 
World species are considered congeneric with the geno- 
type. In view of the confusion presently holding among 
the bethylid genera, there seems little excuse for separat- 
ing the American forms at this time. For better character- 
ization, the males of the New World forms need to be dis- 
covered and the Old World ones to be redescribed. 
The females of the New World forms are slender, yel- 
lowish or ferrugineous wingless wasps of very small size. 
The head is oblong and more or less depressed. The eyes 
are small and placed near the anterior quarters or fifths 
of the sides of the head. The antennae are 13-segmented, 
incrassate, the scapes especially so, and are inserted in 
pits close together on the extreme anterior part of the 
head. The clypeus and adjoining structures are much 
reduced and modified by fusion, so that the two depressions 
ventral to the processes upon which the antennae are 
inserted have become separated by a small but sharp verti- 
cal plate. The legs are of normal bethylid type, without 
peg-like spines. 
The fusion of the clypeus with adjoining structures, the 
reduction of eyes and lack of strong pigmentation, and the 
incrassation of the antennae are modifications for hypo- 
gaeic or other cryptobiotic existence found also in other 
hymenopterous groups. Among the ants, certain dorylines 
and cerapachyines show similar modification, and the 
structural similarity has been used to support contentions 
that these two subfamilies are close in a phylogenetic 
sense. It need only be pointed out that the modifications 
shown by other, clearly distant groups like Discothyrea 
among the ants and Psilobethylus among the bethylids dem- 
onstrate that the phenomenon is one of multiple conver- 
gence and that it may not be trusted in attempting to 
establish relationships of systematic significance. 
Little is known concerning the biology of the American 
forms. It is assumed that our forms follow the bethylid 
pattern of “parasitism” on other insect larvae. The col- 
lection data and obvious structural features of our fe- 
males indicate that the hosts are hypogaeic in habit, at 
least during the stage at which attacked. The American 
