50 Trans. Acad. Sci. of St. Louis. 
it is a small species about 7 mm. in length and occurs in 
Arizona. I have never seen it. 
Lissobiops n. gen. 
The very fine and rather rare species named Cryptobiwm 
serpentinum by LeConte, is distinguished from any known 
form of Hesperobium by four characters of greater or less 
importance, which together appear to demand generic sepa- 
ration. The most important of these characters is probably 
the medially interrupted side-margins of the pronotum, the 
latter being bounded laterally by a continuous fine reflexed 
bead in Hesperobium. The second is the imperfect pleural 
fold of the elytra, which comes far from attaining the infra- 
humeral part of the inflexed sides; the third involves the 
narrow neck, which however is probably of less significance 
in this case than would seem apparent and the fourth con- 
cerns the general scheme of coloration, which is unique 
among our Cryptobia, and, bearing in mind the extreme con- 
stancy of the color scheme in some other parts of the Pae- 
derini, such as Paederus for example, this character, which 
so affects the general habitus of the species, is probably of 
considerable importance from a generic viewpoint. Lissobiops 
resembles Hesperobium in its bidentate mandibles, but the 
basal joint of the antennae is even longer than in any species 
of that genus. The single species known thus far may be 
described as follows :— 
Body slender, convex and fusiform, highly polished throughout, pale 
testaceous in color, the anterior two-fifths of the head, the prothorax, 
a subquadrate spot at the scutellum and the entire first, fifth and sixth 
ventrals deep black; legs extremely slender, pale flavate; antennae 
flavo -testaceous, joints two to six black; head narrow, elongate, sub- 
rhomboidal, moderately narrowed before the eyes, which are moderate 
in size and prominence, the basal joint of the antennae rather longer 
than the next four combined and almost as long as the extreme width 
of the head; punctures small, very feeble and extremely sparse through- 
out; prothorax elongate, narrower than the head, rather strongly 
narrowed anteriorly from the middle, the sides arcuate, the apex much 
narrower than the base, the punctures feeble, very remote, with a more 
close-set series along the broad median impunctate area; elytra not 
quite as long as the prothorax but much wider, slightly elongate, 
