METHOD OF DETERMINING GENERA. 
181 
black, and so hirsute as to have led Bay (wanting the 
knowledge of the use of the trophi and posterior shanks) 
to unite the one he knew with his Bombylii; their males 
are fulvous, and the latter have a remarkable elongation 
of the intermediate tarsi, from one of the joints of which 
also a tuft of hair or a loose lateral fringe projects, giv¬ 
ing them thus a wider expansion, and the use of which 
is prehensile, the same as that for which the anterior 
tarsi in some of the Megachiles and in our single Anthi- 
dium receive their dilatation. This structure has also 
the effect of adding very considerably to the elegance of 
their appearance when they are in fine condition. 
The male Apathi can only be distinguished from the 
male Bombi by familiarity with specific characteristics, 
or by the examination of the trophi. But the former 
is the more certain mode of separation, as the trophi 
in Bombas vary in some species, but not sufficiently to 
authorize generic subdivison. General appearance will 
mark where they approximately belong. The length of 
their anteume sufficiently distinguishes them as males, 
and they may be taken with impunity in the fiugers 
from flowers for examination, being, like all the male 
aculeate Hymenoptera , unarmed with stings. The female 
Apathi may be superficially distinguished from the female 
Bombi , which they most resemble, exclusively of the 
generic characters of the convex and subpubescent ex¬ 
ternal surface of the posterior tibiae and the trophi, also 
by their abdomen being considerably less hirsute than 
that of the genuine Bombi, in which it is entirely covered 
with dense shaggy hair, whereas in Apathus there is a 
broad disk upon its surface nearly glabrous. If I re¬ 
member rightly, it is the male Ajjathi only, and not the 
male Bombi, which emit on capture a pleasantly fragrant 
odour of attar of roses. 
