28 Trans. Acad. Sci. of St. Louis. 
ADEROBIUM n. gen. — The structure of the basal parts of 
the head, short basal joint of the antennae and type of ely- 
tral sculpture, isolate this genus completely; it is founded 
upon the Amazonian Cryptobium angustifrons, of Sharp. 
Homogorarsus Hochh. — The remarkable structure of the 
antennal joints and absence of any well-defined beading of 
the elytral suture, as well as some minor structural features, 
such as the form of the mentum, will readily serve to sepa- 
rate this genus from Hesperobium, which it strikingly resem- 
bles in facies and general organization. The type is A. 
chaudoiri Hoch., a male of which from Lenkoran is before 
me. The sexual characters are peculiar, the fifth ventral being 
feebly impressed in the middle and with a very abruptly formed 
median emargination at the transversely rectilinear apex, the 
emargination almost exactly circular in form, the opening being 
narrower than its greatest width; the emargination of the sixth 
ventral is somewhat as in our Hesperobium cinctum Say. It 
has been stated that the genus Spirosoma Mots. — Bull. Mosc. 
1858, p. 206 — described from India, is the same as Homoeo- 
tarsus, but the statement that the tarsi are one-half shorter 
than the tibiae, with the first four joints triangular and 
equal, the last as long as the two preceding combined, would 
seem to indicate generic difference, for even if the tarsus 
referred to be the anterior, it would not be true of Homoeo- 
tarsus, where the basal joint is still notably longer than the 
second. Itisalsosaid of Spirosoma that the second and third 
antennal joints are equal in length, the fourth shorter, 
whereas in Homoeotarsus the second joint is much shorter 
than the third and equal to the fourth. 
EucryPrina n. gen.— This genus is founded upon the 
Amazonian Cryptobium opacum, of Sharp, and is described 
above from a single headless specimen. As the peculiarities 
of the elytra, referred to in the description, are of generic 
value, this mutilation is not so important, but the cephalic 
characters are doubtless also distinctive. There is no trace 
of the sutural beading and juxta-sutural impressions so char- 
ateristic of Hesperobium. 
Pyconocrypra n. gen.— The type of this genus is one of 
