AMERICAN COLEOPTERA. 289 



la its general aspect this species resembles assimilis but the elytra 

 are more decidedly striate and the form less robust. The punctures 

 of the alternate intervals are also more approximated so that the 

 distance between them is scarcely more than the width of the interval, 

 while the distance is double that in the other species. In its sexual 

 characters it approaches collaris but it is a more oblong species than 

 either that or curvata. 



Two specimens, Owen's Valley, California. 



A. collaris Lee. — Regularly oval, slightly oblong, not very convex, piceous 

 to rufous, shining. Head sparsely punctate, vertex with an arcuate row of 

 coarser punctures. Antennal club always darker. Thorax twice as wide as 

 long, narrowed in front, wider at middle than at base, apex emarginate, sides 

 and base arcuate, hind angles obtuse, surface sparsely punctate, a few coarser 

 punctures at sides of base. Elytra oval not much wider than the thorax, sides 

 moderately arcuate, surface with eight striae of closely placed punctures, the 

 eighth somewhat interrupted at base and with a rather long subhumeral stria 

 which joins the margin, intervals slightly convex very sparsely punctulate, 

 the alternate intervals with coarse distant punctures. Metasternum and ab- 

 domen very finely alutaceous and sparsely obsoletely punctulate. Length 

 .08— .12 inch; 2—3 mm. 



Male. — Anterior and middle tarsi slightly dilated. Posterior femora rather 

 slender, simple, the tibiae long and slender, straight at base, arcuate at apical 

 third rather abruptly and somewhat thickened. 



Female. — Tarsi slender, posterior tibiae shorter than in the male and straight. 



This species may be compared to a diminuative valida which it 

 resembles in its form and nearly in sculpture. The sexual char- 

 acters of the one are a reproduction of the other except as to the 

 form of the femur. As in all the species forming the bulk of 

 the genus the sexual characters of the male afford the only true 

 means of separation. 



Occurs in New Hampshire, Canada, Colorado, California and 

 British Columbia, and is a little variable in its elytral sculpture 

 in the various localities, in some the punctures of the strise are 

 subcrenate. 



A. curvata Mann. — Regularly oval, very little oblong, pieeous or rufo- 

 piceous, shining. Head nearly smooth, with four coarser vertical punctures. 

 Thorax twice as wide as long, broadest at base, apex slightly narrower 

 sides and base feebly arcuate, hind angles rectangular but not prominent 

 surface very obsoletely sparsely punctulate, nearly smooth, a few obsolete 

 larger punctures at sides of base. Elytra regularly oval, not wider than 

 the thorax, surface with eight strise of not very closely placed punctures 

 the second and third sinuate, a short subhumeral stria, intervals flat, obso- 

 letely sparsely punctulate, the alternate with coarser distant punctures. Body 



beneath very finely alutaceous, sparsely obsoletely punctulate. Length .12 



.14 inch; 3 — 3.5 mm. 



TRANS. AMER. ENT. SOC. VIII. (37) SEPTEMBER, 1880. 



