CRABRO PUBESCENS, SHUCK., AND INERMIS, THOMS. le 
are exactly alike in all our males, and I can find nothing else 
distinctive of this nature, although the male characters of allied 
species of Crabro are generally most distinctive, I do not think 
it possible to retain the name inermis. 
The following notes in connection with my paper in Trans. 
Ent. Soc., above referred to, may be useful, as 1 have now been 
able to examine many more specimens. 
Metacrabro lituratus, Pz. There is a very small but suffici- 
ently distinct tooth on the upper edge of the mandibles of the 
female before the middle, and therefore this sex should have 
been placed (as was the male) under the same heading as 
M. 4-cinctus (interruptus, Saund.), and not associated with the 
species of Clytochrysus in any respect whatever. 
In Thyreopus cribrarius and scutellatus, male, the spinose 
appearance of the base of the mandibles is best seen when the 
face is viewed obliquely from behind the clypeus; in peltarius 
the mandibles appear merely bent or geniculate towards the 
base in this aspect. 7’. scutellatus, male, has only subfusiform 
antenne, and lacks the conspicuous clothing of hair on the 
flagellum beneath basally. Its clothing is unusually short for 
the group Thyreopine. 7’. cribrarius alone has spots without 
lines on the dilated tibiz. In scutellatus, female, the anterior 
lateral angles of the pronotum are sometimes faintly prominent, 
but not acutely so as in peltarius, whilst its unspotted black 
basal segment is characteristic. 
In my table of the male sex I referred Crossocerus ovalis, 
Lep. (anzius, Wesm.), to the group of C. varius, which was 
defined by the tubercles of the mesopectus. C. ovalis, male, 
however, varies in this respect, for in some specimens I have not 
been able to detect the minute tubercles or spines even with a 
compound microscope, while in others I can see them with a 
lens. In the case of other species these tubercles are better 
developed in the female than in the male, so it is not surprising 
that, being very small in female ovalis, they should be absent in 
the male. The males therefore of the varius group would have 
been better characterized by the form of the seventh dorsal 
abdominal segment. This has a pygidial area defined by fine 
raised lines, which is not the case in C. wesmeli and elongatulus. 
A variety of the latter with entirely black hind tibiz is found in 
the North of England, and corresponds to the inermis variety of 
pubescens. 
In C. ovalis, female, and probably in some other of the 
species with bidentate mandibles, the teeth may be obsolete and 
the mandibles simply blunt at the apex, and this is also some- 
times the case with some of the tridentate species, but in the 
latter case the true nature of the mandibles is generally easily 
determined by the presence of the grooves, which run back from 
the teeth, so that no great difficulty arises in separating the 
