the classification of British Crabronidae. 395 
large, deepish, very distinct, subtriangular, dull; mandi- 
bles with a very distinct tooth on the inner edge, 3-dentate 
at apex ; basal abdominal segment not unusually long, 
the spiracles wider apart than the distance to the base 
of the segment. 
Acanthocrabro, gen. nov., A. vagabundus, Panz. 
39 (38). Length of transverse cubitus very much less than the 
distance between its extremity and the recurrent nervure ; 
pygidial area much less narrowly prolonged apically ; sides 
of the head above much and widely impressed ; the super- 
orbital foveae smooth, placed in these impressions, large, 
but sometimes ill-defined; mandibles 3-dentate, and with 
a feeble angulation on the inner margin; basal abdominal 
segment narrow and elongate, the distance between the 
spiracles less than that from them to the base of the 
segment rises ear . .  . Cuphopterus, Mor. 
40 (41). Superorbital foveae ahem ctly margined on the inner side, 
so as to form a distinct longitudinal division of the lateral 
depressions of the head in which they are placed. 
C. signatus, Panz. 
1 (40). Superorbital foveae ill-defined inwardly, not forming a 
raised line . . . . CO. dimidiatus, Fab. 
42 (17). Occipital margin pradnebe # its apex beneath the head 
into a prominent spine or angle; mandibles simple at the 
apex; pygidial area flat, triangular, the margins fine, the 
surface dull, microscopically granulate, and with sparse 
large punctures. 
Hoplocrabro, Thoms., Hoplocrabro 4-maculatus, F. 
In the Thyreopinae the relationship of Blepharipus 
(Coelocrabro) gonager, B. aphidum and B. carbonarius to 
the typical B. ngritus, etc., seems to me remote, while the 
first named (gonager) is also remote from the two following. 
C. wesmaeli and elongatulus will probably be found generi- 
cally distinct from the rest of Crossocerus. A more exten- 
sive coliection of the small black species of America is 
necessary before these points can be decided. 
RHOPALINAE. 
3d. 
| (2). Antennae highly modified, third joint very small, notstrongly 
divided from the large and long fourth joint, which is 
strongly widened from the base, the fifth elongate and 
