114 Trans. Acad. Sci. of St. Louis. 
Eulathrobium n. gen. 
We begin here a series of genera differing radically from 
those which precede in having a strong cariniform line on the 
flanks of the elytra, parallel to and not far from the lower 
edge. This very important character has been referred to 
previously by several authors, notably Dr. Sharp, in ex- 
pounding the Amazonian and Mexican Paederini, but I am 
not aware that it has been employed Litherto in defining 
genera. The genera without this line are more boreal in 
habitat and equally characteristic of the old and new world 
subarctic faunas, but those possessing the line are more 
southern in habitat, as a rule, and probably originated in 
America; only one genus — Lobrathium Rey, —is common 
to the nearctic and palaearctic regions of the globe, and this 
is more northern in its range than any other, probably 
crossing from America to Asia by way of Bering Strait. 
The genus Hulathrobium consists at present of a single 
species, one of the largest and finest of our Lathrobia; it may 
be described as follows :— 
Form broad, parallel and somewhat feebly convex, deep black throughout 
the legs dark brownish-rufous, the antennae and palpi black, with the 
joints rufous at base; lustre shining; head well developed, wider than 
long, broadly arcuato-truncate at base, the angles very broadly rounded, 
the sides becoming parallel and broadly arcuate behind the eyes, which 
are moderately large, the punctures rather coarse and close-set 
throughout, excepting a small smooth area on the vertex; antennae fili- 
form, moderately stout, about as long as the head and prothorax, the 
medial joints three-fourths longer than wide, obconic, a little shorter 
in the female; protborax not quite as wide as the head and only very 
slightly longer than wide, broadly suboval, the sides feebly converging 
and arcuate posteriorly from the very broadly rounded and obsolete 
apical angles, the punctures coarse, deep and not very sparse, the 
median smooth line distinct, narrow, not defined by series; elytra large, 
quadrate, parallel, distinctly wider than the head especially in the 
female, about a third wider than the prothorax and a fourth longer in 
the male, nearly a third longer than the prothorax in the female, the 
punctures moderately coarse, strong, unusually close-set and arranged 
without trace of order, the surface shining; abdomen parallel and 
straight at the sides, but little narrower than the elytra, finely, rather 
closely punctured but somewhat shining; legs rather long, only moder- 
ately stout. Male with the fifth ventral somewhat broadly and feebly 
