LeConte.] 600 [April 18, 
Tampa, Florida. Smaller aud narrower than the other 
species, having much the form of Ptilium. 
22. Lathridius opaculus. Elongate, blackish piceous, opaque. 
Antenne one-half longer than the head. Prothorax slightly convex, wider 
than long, a little narrowed behind, sides rounded in front, subsinuate 
behind the middle, margin not reflexed ; disc transversely impressed near 
the base. Elytra elongate-oval, one-fourth wider than the prothorax, strize 
fine punctulate, interspaces flat, disc oblique and broadly impressed in front 
of the middle ; sutural stria more deeply impressed behind the middle. 
Length 1.5 mm.; .06 inch. 
Detroit, Illinois, Mass., and Maryland. In some speci- 
mens the prothorax is obsoletely channeled. 
23. Lathridius maculatus. Less elongate, blackish piceous, 
opaque. Head and prothorax broadly channeled, the latter feebly convex, 
wider than long, narrowed behind. sides finely serrate, not reflexed, 
rounded in front, sinuate towards the base; disc deeply transversely im- 
pressed behind the middle. Elytra nearly one-half wider than the pro- 
thorax, truncate at base, widest just behind the middle, sub-depressed, strize 
fine, punctured, sutural and two outer ones deeper, especially near the tip; 
color testaceous, tessellated with black quadrate spots, margin blackish; 
disc deeply obliquely impressed near the base. Length 1.9 mm.; .075 
inch. 
Detroit. Allied to these two species is the following : 
24. Lathridius duplicatus. Moderately elongate, blackish pice- 
ous, opaque. Prothorax one-half wider than long, narrowed behind, sides 
finely serrate, rounded in front, oblique behind, hind angles obtuse ; dise 
feebly impressed in front of the middle, and with a shallow transverse im- 
pression behind the middle. Elytra one-third wider than the prothorax, 
elongate-oval, striae composed of punctures, not regularly arranged, and 
approximated by pairs; the sutural and two outer ones are slightly im- 
pressed near the tip. Legs rufo-piceous. Length 1.9 mm.; .075 inch. 
Illinois, and Detroit. This and the two preceding species 
belong to the group Hnicmus Thomson, in which the pros- 
ternum extends to the hind margin of the prothorax, the an- 
tennee are shorter than the head and prothorax, with the 
three outer joints enlarged ; and the prothorax is not strong- 
ly margined at the sides. 
In LZ. sculptilis only two joints of the antenne form the club; it thus 
belongs to Coninomus Thomson. In JF. liratus, a still more remarkable 
peculiarity, first mentioned to me by Dr. Horn, is seen; the prosternum 
extends ‘only a short distance behind the coxze, and is enclosed by the 
epimera, which coalesce on the median line as in Rhynchophora; the front 
