Genera and Species of Coleoptera. 51 
In 1857 I briefly characterized this genus, at the same time de- 
scribing three species, all Asiatic. I do not see that I can add any- 
thing really essential to those characters now. The genus is a very 
natural one, and is allied to Hrythrus, but with an ovate-elongate or 
almost subcylindrical prothorax; elytra slightly contracted in the 
middle, much more convex, and with a broad emargination externally 
near the shoulder. The palpi also are longer and more unequal. The 
antenne vary in length, but are longest in the males, although 
scarcely so long as the body. The pro- and mesosterna are simple. 
Professor Westwood has given an excellent figure of Pyrestes exumius 
in the work above quoted (pl. 22. fig. 3). 
Eryturvs [ Cerambycide]. 
White, Cat. Col. Ins. Brit. Mus. Longicornia, p. 142. 
Erythrus congruus. 
E. niger ; prothorace elytrisque coccineis, illo nigro sex-maculato et medio 
breviter carinato. 
Hab. Hong Kong. 
Slightly depressed, irregularly and closely punctured, black; pro- 
thorax and elytra bright scarlet, the former nearly equal in length and 
breadth, with six black spots, four on the disk and one on each side, 
the middle with a short elevated line; scutellum transverse; elytra 
moderately long, an elevated carina running from each shoulder to near 
the apex, which is rounded with its edges minutely serrated; body 
beneath entirely black, very closely and irregularly punctured; legs 
black, tarsi of the intermediate pair longer than their tibie. Length 
9 lines. 
From Saperda? bicolor, Westw., this insect differs in being entirely 
black beneath, in its six-spotted prothorax with a short elevated 
line in its middle, in the more decidedly elevated and longitudinal 
carina which occurs on each elytron, and in the general vitreous 
sort of transparency which in certain lights and under a strong lens 
glistens over its surface, especially on the elevated lines of the pro- 
thorax and elytra. It will serve to show the uncertainty of cha- 
racters generally thought to be of generic value among the Longicorn 
families that, notwithstanding the close affinity of these two Hrythri, 
amounting at the first glance almost to identity, the one, Z. bicolor, 
has the epistome very distinct, while in the other it is apparently 
wanting. Hrythrus Fortunei, White (the only other Zrythrus having 
the head black), is a narrower and smaller species, with a longer pro- 
thorax and darker colour. 
