INSECTA. 
464 
The eighth tribe, that of the Byrrhii, differs from the preceding 
in the perfect contractility of the legs ; the tibiae are susceptible of 
being flexed on the thighs, and the tarsi on the tibiae *, so that when 
thus folded and pressed against the body, the animal seems to be in- 
animate and entirely destitute of feet. The tibiae are usually broad 
and compressed. The body is short and convex. 
This tribe is chiefly composed of the genus, 
Byrrhus, Lin. 
Those species which form the 
Nosodendron, Lat. 
Are removed from the others by their entirely exposed, very large, 
and scutiform mentum. Their antennae terminate abruptly in a 
short, perfoliaceous and triarticulated club. They are found in 
wounds of trees, of the elm particularly f. 
Byrrhus, Lin. — Cistela, Geoff. 
The true Byrrhii differ from the preceding Insects in their men- 
tum, which is of an ordinary size and interlocked (at least partially) 
by the praesternum, whose anterior extremity is dilated. 
In some, the antennce enlarge insensibly, or terminate in an cn- 
gated club formed of from five to six joints. 
B. pilula, L.; Oliv., Col. II, 13, 1, 1. From three to four 
lines in length ; black beneath, blackish-bronze or soot colour 
and silky above, with little black spots mingled with lighter ones 
arranged in lines. 
M. Waudouer has detected the larva of a variety of this spe- 
cies. It is narrow and elongated ; the head thick ; the plate of 
the first segment large, and the two last longer than the others. 
It lives in Moss. 
A second species — striato punctatus, Dej. — with similarly 
formed antennae, constitutes a separate division, on account of 
its tarsi, of which the fourth joint is very small and concealed be- 
tween the lobes of the preceding one. 
The antennae of another species, very small and covered v/itli 
hairs, terminate in a triarticulated club. It forms the genus 
Trinodes, MegerL, and Dej. |. 
On similar grounds we might alse separate from the Byrrhii 
some other analogous species ||, in which the antennal club con- 
sists of but two joints, the last much the thickest and nearly glo- 
bular. 
* 111 the Anthveni all the tibiae fold against the posterior side of the thighs ; hut 
in the others, the two that are anterior are flexed towards the head, and the other 
behind. 
'h Lat., Ib., II, p. -13 ; Oliv., Encyc. Method., article Nosodendre. 
;j; Anthrenxis hirtiis, Fab.; Pauz., Faun. Insect. Germ., XI, 16. 
II Byrrhus erinaceus, Ziegl. ; — B. setiger, Illig. 
