152 Trans. Acad. Sci. of St. Louis. 
wide, the anterior not in the least dilated or thickened; species very 
minute, not distinctly punctured; male sexual characters nearly as in 
Sciocharis, except that the apex of the fifth segment is lobed in the 
middle. Southern Atlantic States......seee cece seee sess SCIOCHAFEllA 
6—Labral teeth small and inconspicuous; prosternum never carinate 
throughout its length except in a few abnormal members of Medon.. 7 
Labral teeth long, acute and very conspicuous; prosternum carinate 
throughout its length; gular sutures converging and most narrowly 
Separated basally..e sees cccccccccecccs secs voce sess seccccceseseveeels 
7— Basal joint of the posterior tarsi equal in length to the second, the 
first four short and subequal, the anterior very slightly dilated; palpi 
normal; gular sutures rather narrowly separated, evenly, feebly arcuate, 
very rapidly diverging at base, most narrowly separated at a little be- 
fore the middie; antennae rather thick, gradually enlarged distally, 
the third joint distinctly longer than the second; eyes moderate; neck 
about half as wide as the head; prosternum not at all carinate at any 
point; integuments very coarsely, densely sculptured and dull, the 
species small in size. Nearctic regions, east of the Rocky Mountains. 
Trachysectus 
Basal joint of the hind tarsi distinctly longer than the second, the tarsi 
MOTE C1ONZALC... -ccccccccee secs voce vcceceservvcces voce secs vesevcessed 
8 — Labrum with a rather broad sinus at the middle including the two teeth, 
which are very small and not as anteriorly prominent as the sides of 
the labrum; species small, with the elytra very small, shorter and nar- 
rower than the prothorax; eyes rather small; neck two-fifths as wide 
as the head; gular sutures well separated and subparallel but obsolete 
or very feeble; antennae short, moderately thick, filiform, not en- 
larged distally, the basal joint thicker than the remainder; prosternum 
rather strongly carinate except anteriorly; posterior tarsi very slender 
and filiform, the anterior slightly dilated; integuments rather coarsely, 
densely sculptured and dull. Appalachian region.........Hemimedon 
Labrum with a narrower median notch, the two teeth more advanced than 
the lateral parts of the edge and not included within the sinus.........9 
9 — Anterior tarsi not dilated but only more or less strongly thickened; sex- 
ual characters very feeble, .... vscsccccceccccceccs cevccscvcccevess sel 
Anterior tarsi strongly dilated, especially in the male; sexual characters 
BtPONT]Y MACK . oes c ccnccs sececcacccncesen vecececsenscpocassecveell 
10 — Gular sutures distant, broadly arcuate, becoming very widely diverg- 
ent toward base and most narrowly separated well before the middle; 
species small, slender in form, polished and sparsely punctate, the 
elytra subequal to the prothorax in size; antennae moderately thick, 
somewhat enlarged distally; labrum very broadly, angularly emarginate, 
* with a small feeble median sinus, the teeth very minute; eyes rather 
well developed; neck a little less than half as wide as the head; ante- 
rior tarsi spongiose beneath in both sexes; hind tarsi slender and fili- 
Form. EUrope..cccccesseccsvecesveceeseeves coceceeeceee.* Hypomedon 
Gular sutures of the same form as in Hypomedon but subobsolete; species 
minute, slender, polished and sparsely, rather coarsely punctate, the 
elytra shorter than the prothorax; antennae normal in structure; lab- 
rum small, truncate, with a distinct rounded median sinus and two well 
