72 
Psyche 
[June 
ft., 18 $ , at flowers of Phacelia heterophylla Pursh, July 16 
to 21, 1928 (J. Bequaert). These insects were active only 
during the warmest hours of the day and in bright sunshine. 
Most of the specimens were observed between 9 A. M. and 
1 P. M. Although many other flowers were carefully watched 
for insect visitors and some species of Pentstemon were 
growing in that locality, P. marginalis was seen visiting 
only Phacelia heterophylla. No male was ever seen near 
the flowers. 
Characters of the Masaridinse 
The subfamily Masaridinse is one of the best-defined 
groups among the Vespidse, or folded- winged wasps. It 
agrees with the other Diploptera in having the first discoidal 
cell (M 4 ) of the fore wing at least as long as the submedian 
(Cu+Cui), the only peculiar character that holds good 
throughout the entire family Vespidse. Yet it should be 
observed that this peculiarity of the wing is not as strongly 
marked, as a rule, in the Masaridinse as in most other sub- 
families of Diploptera (with the exception of the Gayellinse 
and Euparagiinse) . The lengthening of the first discoidal 
cell is evidently correlated with the longitudinal plaiting 
of the wing, a feature not or but faintly shown by most 
Masaridinse. In this connection it is noteworthy that in the 
few masarid genera (Quartinia and Celonites) in which 
the fore wings are strongly plaited, the first discoidal cell 
is very long. The wing of Celonites, for instance, differs 
hardly in this respect from that of Vespa. 
The one distinguishing character of all Masaridinse, not 
found elsewhere among the Diploptera, is the simplified 
venation of the hind wing, in which the transverse median 
vein (M 3 ) is straight and not angulate, the discoidal vein 
(m-f-M?) being apparently wanting. But, as shown by 
Bradley (1922, Op. cit., p. 374), the position of the pre- 
axillary excision seems to warrant the conclusion that 
the apical section of the anal vein (Mi-j-Cui +2 -f- 1st A + 
2d A) has become lost, and not the true discoidal vein 
(m+M 2 ). The hind wing must therefore be regarded as 
highly specialized and not as primitive. 
In the remaining characters, the Masaridinse exhibit a 
