Patton.] 402 [January 21. 
female being unlike that of Cerceris, in the shorter ciliation of the 
anterior tarsi of the male and the simple posterior tarsi of the male. 
In the entire eyes, the approximate antennae inserted high above 
the clypeus, the flat front of the male, the erect fringe on the _ 
clypeus of the male, and the short submedial cell of the posterior 
wings, this genus differs from Philanthus and agrees with Cerceris 
and Eucerceris. In the other characters the male agrees with Phi- 
lanthus (or, rather, with the American section of that genus which 
has been named Cheilopogonus by Westwood and Anihophilus by 
Dahlbom); but the female differs from Philanthus in the 5-dentate 
clypeus, the straight edge of the labrum, and the presence of an en- 
closure on the sixth segment of the abdomen. 
The anterior tarsi of Philanthus are armed externally with a 
fringe of long spines, and the male to some extent shares this char- 
acter with the female, the spiné at the apex of the third joint extend- 
ing well beyond the tip of the fourth joint. In both sexes of Cer- 
ceris these spines are short, and the tarsal joints are more robust 
than in Philanthus. In these characters Aphilanthops ¢ is inter- 
mediate, the tarsal joints not being so robust as in Cerceris, and the 
spine at the tip of the third tarsal joint, extending only to the tip of 
the fourth joint; but the female of Aphilanthops agrees with Phi- 
lanthus. 
The antennae of Aphilanthops are not so closely approximate at 
their insertion as in Cerceris, and some species of Eucerceris, but 
are as close as in Luc. canaliculatus (Say), and Euc. supertus Cress. 
The labrum of Aphilanthops S is smaller than is usual in Philan- 
thus 3, but is not, as in the ¢ of Eucerceris and Cerceris, a mere 
transverse border of the membranous lobe which lines the under 
side of the clypeus. In Philanthus 3 the labrum has a median notch 
or sinuation. In the female of Philanthus the labrum has three 
slight sinuations on the anterior margin, that in the middle being 
narrow and sharp. In Cerceris ¢ the margin of the labrum is tri-sin- 
uate or tri-emarginate. The median sinuation is commonly broad and 
shallow (as in bicornuta, nigrescens, clypeata and dentifrons); the 
lateral sinuations may be slight (asin nigrescens, clypeata, etc.), 
or as large as the median sinuation (as in bicornuta) and angular. 
In C. compar the labrum of the female is much produced, the 
median. portion produced the most, and the median sinuation 
replaced by an angular notch ; and the labrum of the male is almost 
as large as is the labrum in the female of other species. The labrum 
