246 Trans. Acad. Sct. of St. Louis. 
rax small, elongate, suboval; prosternum well developed before the 
coxae, evenly convex, not carinate; elytra parallel, well developed; 
abdomen at base as wide as as the elytra, long, gradully tapering; legs 
very slender, rather short, the anterior tarsi not in the least dilated, 
the posterior very slender, filiform, two-thirds as long as the tibiae, 
the joints cylindric, closely united, the basal joint subequal in length to 
the next two together and rather longer than the fifth; claws small. 
Warmer parts of North and South America........++........kchiaster 
Fifth ventral not much elongated, wider than long, the sixth small; eyes 
very small, miuutely setulose; sculpture and lustre nearly as in Echias- 
ter; body very small in size, slender; head well developed, oblong, 
sinuato-truncate at base; labrum quadridenticulate, short, the median 
teeth longer than the outer; antennae extremely short, not as long as 
the head, nearly as in Echiaster; mentum small, transversely subquad- 
rate, convex, the side margins bisetose, not distinctly elevated or pro- 
duced, the anterior margin apparently finely denticulate at each side; 
labial palpi very small, slender, the maxillary moderately developed 
with the second joint arcuate, inflated distally, subglabrous, the third 
longer than the second, securiform with its anterior side strongly 
arcuate in the middle, the posterior nearly straight, the fourth joint 
extremely minute and abbreviated but slender and aciculate; neck 
relatively less slender, scarcely a fifth as wide as the head; prothorax 
small, with more pronounced angles than in Echiaster, the elytra nearly 
similar, the prosternum well developed before the coxae, carinate pos- 
teriorly; legs short and slender, the tarsi nearly as in Echiaster. South- 
ern Atlantic and Gulf States......seeesecesceccecee rece o LEPtogenius 
The above diagnosis of Hchiaster is drawn from our only 
species, the very small /udovicianus, to be described below, 
and it is probable that other genera and subgenera are repre- 
sented among the numerous Brazilian species. 
Echiaster Erichs. 
The principal characteristic features of this genus are the 
narrow, prolonged and frequently subtubuliform fifth and 
sixth ventral segments and the extremely large eyes, which 
are even more conspicuous or relatively larger than in 
some species of Stenus. The only representative within our 
boundaries may be described as follows : — 
Form slender, moderately convex, densely dull in lustre, pale red-brown in 
color throughout, the prothorax usually rather paler than the rest of 
the body; head as wide as long, the eyes convex, prominent, at less 
than half their own length from the base and half as long as the entire 
head and labrum; sides behind them converging and strongly arcuate 
