EXTERNAL ANATOMY OF INSECTS. 659 
are disproportionally dong and slender, as in Phalan- 
gium Opilio and some species of Gonyleptes*: those 
of others are disproportionally short, as in Elater, &c. 
With regard to their relative proportions, the most ge- 
neral rule is, in Hexapods, that the anterior pair shall 
be the shortest and most slender, and the posterior the 
longest and thickest; but there are many exceptions: 
thus, in Acrocinus longimanus, Clytra longimana, &c., in 
the male the arms are the longest; again, a thing that 
very rarely occurs, in the same sex of Anthophora retusa 
the zntermediate legs are the longest ®; but in Rhina bar- 
birostris and many weevils they are the shortest: in 
Saperda hirtipes® the hind-legs are disproportionally 
long: with regard to thickness, they are in general ex- 
tremely slender in Cicindela, and in the Scarabeide very 
thick. In Goliathus Cacicus the arms are more robust 
than the four legs4; in Gyrinus the latter are more dilated 
than the former; in many Rutelzde, and particularly in 
the celebrated Kangaroo beetle (Husceles ? Macropus) 
the hind-legs are much the thickest; in certain wee- 
vils from Brazil (Plectropus K.*), the intermediate pair 
are more slender than either the arms or the posterior 
pair. 
6. Clothing. The hairs on the legs of insects, though 
at first sight they may seem unimportant, in many cases 
are of great use to them, both in their ordinary avocations 
and their motions: but as most of these were sufficiently 
* See above, p. 37. 
® Monogr. Ap. Angl. i. t. xi. Apis * *, d. 2. a. f. 18. 11. 296—. 
© Oliv. Ins. 68. t. i. f. 8. « hid. n. 6. t. iv. f. 22. 
© [have changed Schonherr’s name for this genus (Leptocerus), 
because it had been previously given by Dr. Leach to a group of 
Trichoptera. 
ZU eZ 
