246 Trans. Acad. Sci. 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 Echiaster 



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 JLeptogeiiius 



The above diagnosis of Echiaster is drawn from our only 

 species, the very small ludovicianus, 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 eye3 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 



