— = 
4 
(9388) ) 
XIII. On the classification of British Crabronidae 
(Hymenoptera). By R. C. L. Perkins, M.A., 
DSc, EZ.8. 
[Read April 2nd, 1913.] 
Prats XIX. 
Tue Crabronidae, owing to the number of their species, 
form a most important part of the British Hymenoptera 
Aculeata, and in the tabular classification that follows, I 
have attempted to show the relationship of the various 
groups, genera and species to one another. Some characters 
that have been very little used by British hymenopterists 
are largely utilised, since I have found them of great 
importance in dealing with exotic species. Edward 
Saunders in his admirable works recognised only two 
genera: Hntomognathus with a single species and Crabro 
including all the others, employing, however, a number 
of subgenera of Crabro in his latest writings. I think that 
Ashmead, following the example of earlier classifiers, was 
correct in considering the Crabronidae to consist of many 
good genera, and also in grouping these genera together 
in divisions of a higher order, which he calls subfamilies, 
and these I have recognised here, without discussing the 
point as to whether the divisions are of subfamily value 
or not, since they are, at any rate, natural. To place our 
British species of Crabro in a single genus appears to me 
precisely the same as if all our butterflies (excluding 
Hespervidae) were assigned to Papilio and a few subgenera 
of this. 
Ashmead’s deep insight into the affinities of the groups 
of Hymenoptera was rarely at fault, but his carelessness 
in the definition of characters of genera, etc., is well known, 
even when the genera themselves are perfectly valid. The 
type of his genus Metacrabro is our well-known species 
Crabro lituratus, the 3 of which he says has no spur on 
the middle tibiae, but an unusual structure of the 2nd 
antennal joint. In neither of these points is he correct. 
The 3 of his genus Xestocrabo, according to specimens sent 
to me from America, is also incorrectly said to be without 
TRANS. ENT. SOC, LOND. 1913.—PaRT Hl. (SEPT.) 
