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Bi 4 
E . 
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7 
Patton. ] 400 [January 21, 
recurved tooth near the base, another large tooth beyond the middle, 
and a small tooth between them. In the male of compacta the tooth 
near the base is as in the female, but the others are absent. 
In Cerceris and Eucerceris the lateral apical borders of the pos- 
terior coxae above (particularly the inner border), are produced — 
into large rostrate carinae between which the narrowed base of the | 
trochanters plays, the posterior trochanters are angulated within, 
and the apex of the posterior femora is dilated to form an irregular 
flange with a flattened posterior face. In Philanthus and Aphilan- 
thops the apophyses of the coxae are small and slender, and the 
femora are not dilated at the apex. 
In all the Philanthinae the insertion of the recurrent nervures is at 
or before the middle of the cells by which they are received, and 
Eucerceris does not differ from Cerceris in this respect, although the 
first recurrent is more commonly inserted nearer the base of the 
“second submarginal cell than in Cerceris. Yet I have a specimen of 
C. deserta Say in which the first recurrent nervure of one wing 
unites with the first transverse cubital nervure, and many species 
show great individual variation in the insertion of the recurrents. 
The characters which I find to separate Cerceris- and Eucerceris 
are: the form of the marginal and submarginal cells; the sexual 
differences in the venation of EHucerceris; the presence of a space 
between the eyes and side lobes of the clypeus in Eucerceris 3 
which is absent in Cerceris; the absence of lateral sinuations on 
the anterior border of the labrum in Eucerceris 2 which are present 
in Cerceris; the mandibles of the female, which in Eucerceris have 
one tooth on the inner margin, and in Cerceris have two or three; 
the presence of transverse median depressions on the abdominal seg- 
ments in Hucerceris which are absent in Cerceris ; the teeth termt- 
nating the carinae which bound the area on the dorsal valve of 
Eucerceris $ which are absent in Cerceris; and the narrowed eighth 
ventral segment of Hucerceris ¢ extending beyond the dorsal valve, 
while in Cerceris the ventral valve is broad and not produced beyond 
the dorsal valve. 
But in Eucerceris cingulatus Cress. ¢ the transverse depressions 
on the abdominal segment are very indistinct, and in Cerceris bicor- 
nuta Guer. & the eighth ventral segment resembles that of Eucer- 
ceris. In many species of Cerceris also, the male mandibles are 
unarmed; and in C. fumipennis Say the labrum of the female is as 
in Eucerceris. 
‘ 
