76 MEMOIRS ON THE COLEOPTERA. 



to the head and but slightly wider than long, the basal angles obtuse and 

 rather rounded; base rounded, the surface evenly convex; elytra trans- 

 verse, with feebly diverging sides, a fourth wider than the prothorax 

 though scarcely longer; abdomen broad, parallel, with arcuate sides, 

 at the middle much wider than the elytra, the margins thin, the tergites 

 short and equal in length. Length 1.5 mm.; width 0.38 mm. Kansas 

 (Mt. Hope). 



Differs from seticornis in its relatively much broader and, in regard 

 to color, sharply bipartite abdomen, also in its smaller, more parallel 

 head, smaller and more slender antennae and in other characters. 



It is more than probable that Myrmedonia fauveli, angustula and 

 recisa should be generically separated from Myrmedonia, because of 

 the total lack of the infra-lateral carinas of the head distinguishing 

 that genus, in which case such named group could very appropriately 

 come under Apalonia as a subgenus. 



Trichiusa Csy. 



Of this genus there are a very large number of species distributed 

 throughout subarctic North America. Trichiusa has a peculiar 

 facies, isolating it from any other American genus and, as far as 

 known to me, it has no closely related European analogue. The 

 following is allied to monticola: 



Trichiusa columbica n. sp. Stout, rather convex, compact, wholly 

 black, the legs but little paler; surface rather shining, the micro-reticu- 

 lation rather coarse and strong, especially on the elytra, feebler on 

 the abdomen; punctures very fine, not dense, indistinct, sparse on the 

 abdomen; pubescence long, coarse and bristling, not dense, dusky; 

 head moderate, convex, impressed on the median line from the centre to 

 the base, wider than long, nearly three-fourths as wide as the prothorax, 

 the eyes small, at much more than their length from the base, the sides 

 straight and parallel, then broadly rounding to the base; antennae short 

 and stout, bristling with many long stiff hairs, blackish, slightly paler 

 basally, incrassate distally, the first three joints decreasing rapidly, 

 the third obconic, fourth and following transverse, the lastogival; pro- 

 thorax well developed, short and strongly transverse, almost as wide as 

 the elytral base, the base rounded, the sides parallel and nearly straight, 

 rounding anteriorly, the surface unimpressed; elytra large, moderately 

 transverse, about a fifth wider and two-fifths longer than the prothorax, 

 the humeri just visibly exposed ; abdomen fully as wide as the elytra, par- 

 allel, narrowing very little apically, with moderately arcuate sides, the 

 tergites short, subequal, the margins well developed. Length 1.5 mm.; 

 width 0.46 mm. British Columbia (Metlakatla), Keen. 



Differs from monticola, from northern Idaho, which it otherwise 



