288 GEO. H. HORN, M. D. 



Also transcontinental in its distribution, occurring in New Hamp- 

 shire, Michigan, Canada, Colorado and Vancouver. 



A. piinctatostriata Kby.— Oval, slightly oblong, convex, shining. Head 

 sparsely punctate with an arcuate row of coarser punctures. Thorax twice as 

 wide as long, gradually narrower from base to apex, the latter emarginate, the 

 base truncate, hind angles rectangular but not prominent, surface sparsely 

 finely punctate, a few coarser punctures along the base at the sides. Elytra 

 oval continuing regularly the curve of the sides of the thorax, surface with 

 eight rows of coarse and closely placed but not crenate punctures, the eighth 

 abbreviated at base with a moderately long subhumeral row of punctures, 

 intervals flat, shining, sparsely punctulate, the alternate with distant coarser 

 punctures. Metasternum finely alutaceous, sparsely punctulate, abdomen shin- 

 ing, very sparsely punctulate. Length .10 inch ; 2.5 mm. 



Male. — Anterior tarsi slightly dilated. Posterior femora simple beneath, 

 neither dentate nor crenate, posterior tibiae straight not diflfering from the 

 female. 



Female. — Anterior tarsi slender. 



This species is peculiar in the almost entire obliteration of sexual 

 differences, the anterior tarsi S are even feebly dilated but quite dis- 

 tinctly broader than the female. Apart from the sexual charac- 

 ters of the male this species is not readily distinguishable from 

 assimilt's by description. It is hov^ever more regularly oval in its 

 outline, the sides of thorax and elytra being in a continuous curve, 

 the body more convex and the surface less deeply sculptured and 

 more shining. 



This species follows assimilis in its distribution. Synonymous 

 with it is Isefa Mann., described from Alaska, that described as the 

 present species is certainly an erroneous determination and is probably 

 Hydnohius suhstriatus Lee. 



A. difflcilis n.sp. — Oblong, rufo-testaceous, shining. Head sparsely punc- 

 tulate with a few slightly coarser vertical punctures. Thorax twice as wide as 

 long, narrowed in front, sides feebly arcuate, apex slightly emarginate, base 

 subtruncate, hind angles obtuse but not rounded, surface sparsely punctulate, 

 with a few slightly coarser punctures near the basal angles. Elytra oblong-oval, 

 sides feebly arcuate, surface substriate, strise with moderate punctures closely 

 placed, eighth stria much abbreviated, continued by coarser more distant punc- 

 tures to base, a rather long subhumeral stria, intervals feebly convex very 

 finely punctulate, the alternate intervals with coarser punctures rather closely 

 placed. Body beneath finely alutaceous, obsoletely punctulate, the abdomen 

 more distinctly. Length .12 — .14 inch; 3—3.5 mm. 



Male. — Anterior and middle tarsi very decidedly dilated. Posterior femora 

 slightly thickened not serrulate nor dentate, the posterior tibise arcuate near 

 the apex. 



Female. — Anterior and middle tarsi more slender and longer than the male. 

 Posterior femora less stout, the tibise shorter, less slender and very slightly 

 arcuate. 



