224 Trans. Acad. Sci. of St. Louis. 
modified, the surface with two small tumescent processes very near the 
apex, separated by about twice their own width, the sixth segment with 
a large simple rounded sinus, nearly three times as wide as deep. 
*Length 3.7 mm.; width 0.7 mm. Massachusetts........biarmatus Lec. 
Nearly similar throughout to the preceding but a little larger, the prothorax 
relatively smaller and less elongate, two-thirds as wide as the head, with 
the polished median line still narrower and distinctly concave; elytra 
larger, quadrate, a third wider and obviously longer than the prothorax. 
Male with the apex of the fifth ventral retilinearly truncate and unmodi- 
fied, the surface with two tumescent processes as in biarmatus, but having 
these processes very much smaller and separated by fully three times 
their own width, the sixth segment with a large and nearly similar 
sinus at tip. Length 3.9 mm.; width 0.75 mm. Lake Superior (Bay- 
field), — Mr. Wickham —and Iowa..............---lacustrinus 2. sp. 
Somewhat similar to the two preceding in general form, piceous, the pro- 
thorax dusky rufous, the abdomen black; head more evenly and semi- 
circularly rounded throughout from eye to eye, the confluent punctures 
somewhat coarser than in biarmatus; prothorax narrower and relatively 
more elongate, the angles very obtuse and rather more rounded, the 
punctures dense and confluent, the median impunctate line much wider 
and wholly unimpressed; elytra more convex and more finely and 
sparsely punctate, a little shorter than wide, with pale apex, rather 
shorter than the prothorax and two-fifths wider, less obviously narrower 
than the head than in biarmatus; abdomen at base slightly narrower 
than the elytra, at about the middle as wide as the latter, less densely 
punctulate and more polished. Male having the apex of the fifth ventral 
rectilinearly truncate, with a very small feeble arcuate lobe at the 
middle, the surface with two transverse and very feeble, densely and 
coarsely setulose tumidities very near and parallel to the hind mar- 
gin, mutually separated by a very narrow space scarcely half as wide 
as either, the sixth segment with a very large simple parabolic sinus 
at tip. Length 3.7 mm.; width 0.7mm. New York (near the city). 
abbreviellus n. sp. 
10 — Median smooth line of the pronotum narrow, the polished elytra sub- 
metallic in lustre. Rather stout, convex, dark piceous in color, the 
abdomen black, the elytral apex narrowly pale, more broadly toward 
the sides, the legs pale luteo-flavate throughout, the antennae dark 
rufous; surface dull, somewhat coarsely, densely and confluently punc- 
tate anteriorly, the elytra and abdomen sparsely, finely punctate and 
polished; head relatively small, rather longer than wide, the eyes large, 
convex and prominent, at about their own length from the base meas- 
ured longitudinally, the contour behind them ogival; antennae mod- 
erately long and slender, distinctly incrassate distally; prothorax 
slightly elongate, fully three-fifths as wide as the head, the sides obtusely 
but very distinctly angulate at two-fifths from the apex, thence very 
feebly converging and straight to basal fifth, then strongly converging 
and sinuate to the base; elytra large, quadrate, parallel, broadly con- 
vex, distinctly wider than the head, three-fourths wider and nearly 
a third longer than the prothorax; abdomen at base distinctly narrower 
than the elytra, the third and fourth segments generally subequal in 
