22o MEMOIRS ON THE COLEOPTERA 



the mesosternum, form a third section, which has fully the status 

 of a separate group. All of the following three species belong to 

 the restricted depurator group as limited above: 



Hister circinans n. sp. Form very broadly rounded and sometimes 

 almost circular, convex, polished, black throughout; head with the punc- 

 tulation extremely fine and sparse, the stria entire; prothorax only moder- 

 ately transverse, with the sides strongly converging from the base and 

 almost evenly arcuate; surface smooth, having a series of fine punctures 

 along the basal margin, the striae well impressed, slightly crenulate, the 

 inner entire, the outer abbreviated, not very close to the margin; elytra 

 only slightly transverse, with very strongly, subevenly arcuate sides, 

 the three entire striae rather coarse, shallow, crenulate, the next three 

 more or less evident apically, the humeral represented by a series of small 

 punctures apically only, the oblique humeral extremely fine but distinct; 

 propygidium with the moderate punctures widely separated, mingled with 

 sparse minute punctulation, those of the pygidium well separated, fine, 

 becoming slightly coarse basally, the entire surface convex and polished; 

 femora in great part finely punctate; sterna and legs as in depurator ; 

 the prosternal truncature in the male broad, transverse and limited by 

 small sharp denticles. Length 6.0-7.8 mm.; width 4-7-5-3 mm - Rhode 

 Island (Boston Neck) and Pennsylvania (Linglestown). 



Allied to depurator but differing in the more broadly subcircular 

 outline, more separated punctures of the more polished pygidia and 

 other characters; the male in outline is scarcely narrower than the 

 female. Depurator is abundant from New York to Colorado 

 (Boulder Co.) and British Columbia (Golden), and I have an ex- 

 ample from New Mexico and another one from Mississippi; the 

 pygidium is alutaceous in lustre. 



Hister perbrevis n. sp. Very short, broad and convex, almost as wide 

 as long, polished; head with the fine punctulation distinct and close-set, 

 the stria entire; prothorax nearly twice as wide as long, the sides strongly 

 converging and feebly arcuate from the base, more rounded at apex; 

 surface minutely punctulate, with a few more evident punctures along the 

 basal margin, except medially; apical stria finely crenulate, the inner 

 lateral fine, entire, the outer as in the preceding; elytra fully two-fifths 

 wider than long, the sides strongly arcuate, the apex broad, with the usual 

 acute reentrant at the suture; three entire striae coarse, the fourth present 

 but often disintegrated in apical half, the fifth in a feeble apical remnant, 

 the sutural short and post-medial, the humeral represented by a series of 

 punctures in apical half, the oblique humeral long but very fine; pro- 

 pygidium with the moderate punctures widely separated, without inter- 

 mingled punctulation, those of the very convex and shining pygidium 

 fine, widely separated, gradually a little stronger basally; prosternum 

 rather wide between the coxae, the mesosternal sinus broad and rather 

 shallow but distinct; anterior tibiae obtriangular, the three teeth extremely 



