Casey — A Revision of the American Paederint. 225 
width to the latter; legs rather long and slender. Male with the fifth 
segment rectilinearly truncate at tip, with a gradually formed short 
and acute median lobe in the form of a cusp, occupying about median 
eighth or ninth of the width, the sixth segment with a simple rounded 
sinus occupying about half the apex and fully four times as wide as 
deep. Length 3.8 mm.; width 0.82 mm. New York, Virginia, Iowa, 
Missouri and Texas (AUStiN).......seeceerseeecoese.++--Gentatus Say 
Median smooth line broader and more conspicuous; abdomen very sparsely 
punctulate and polished; elytra finely and sparsely punctate and strongly 
shining but never metallic in lustre; punctures of the head and pronotum 
rather coarse and strongly, longitudinally confluent......-csce.+eeeeell 
11 — Elytra large, slightly wider than the head.......ssseeseceseesesseel2 
Elytra small, evidently narrower than the head.....-ssesse sees seceeeeeelB 
12 — Form moderately stout, blackish-piceous in color, the elytral apex 
and legs throughout pale luteo-flavate, the antennae pale rufous; 
head somewhat longer than wide, rather broadly ogival behind the 
eyes, the latter convex and prominent, at their own length from the 
base measured longitudinally; antennae rather thick, distinctly 
incrassate distally; prothorax nearly as in dentatus, two-thirds as wide 
as the head; elytra scarcely as long as wide, slightly wider than the 
head, parallel, two-thirds wider than the prothorax and a third longer; 
abdomen at base obviously narrower than the elytra, the third and 
fourth segments as wide as the head; legs only moderately long and 
slender. Male with the apex of the fifth ventral broadly, feebly sinuate 
in median third, with a broad and obtusely angulate tooth gradually 
formed at the bottom of the sinus, the surface of the process slightly 
tumid and polished; sixth segment broadly, cylindrically impressed 
along the middle, with an apical sinus nearly a third as wide as the seg- 
ment and about twice as wide as deep, subtriangular in form but with 
the angle distinctly rounded. Length 3.75 mm.; width 0.78 mm. Rhode 
Island (Boston Neck).....ces.ececceeceeccesceecees LUCHIENtUS D. Sp. 
Form and size nearly similar to luculentus but deep black throughout, the 
elytra and abdomen highly polished, very finely, sparsely punctured, the 
former without paler apex except very faintly toward the external angles, 
the femora and tarsi pale honey- yellow, the former toward tip and the 
entire tibiae picescent, the antennae dusky; head nearly similar but more 
broadly and obtusely ogival at base, the eyes larger and at less than 
their own length from the base; antennae more slender and less in- 
crassate; prothorax nearly similar; elytra quadrate, parallel, fully 
as long as wide, only just visibly wider than the head, three-fourths 
wider and two-fifths longer than the prothorax; abdomen nearly as in 
the preceding, the legs rather longer and more slender. Male unknown. 
Length 3.6 mm.; width 0.75 mm. Mississippi (Vicksburg). 
nigrolucens o. sp. 
13 — Form somewhat similar to the two preceding, smallerin size, black in 
color throughout, the elytra and abdomen highly polished and sparsely 
punctulate, the former pale only at the external apical angles, the legs as 
in nigrolucens, the antennae moderately slender, distinctly incrassate and 
somewhat paler rufous; head rather acutely ogival behind the eyes, 
which are very large, convex and prominent and at scarcely their own 
