72 GEO. H. HORN, M. D. 



more arcuate sides and less convex disc. With this species I unite 

 verna Cand., the difterences being sexual. 



Occurs in California, Oregon and Vancouver. 



A. dilaticollis Motseh. — Black, feebly shining, sparsely clothed with 

 short black pubescence. Form parallel. Thorax as broad as long, sides arcu- 

 ate, hind angles divergent, carinate: surface densely and very equally punc- 

 tured; beneath densely punctured on the flanks without smooth space. Pro- 

 sternal iBucro horizontal, mesosternum moderately prominent. Elytra striate, 

 striae finely punctured, intervals nearly flat, moderately densely puuctulate. 

 Length .54 — .66 inch ; 14—17 mm. 



I have seen four specimens of this species all of which appear to 

 be females. The punctuation of the thorax is even denser and finer 

 than in coracinus. The divergent angles will distinguish it from the 

 next species, which also differs in its pubescence. 



Occurs in Middle California, 



A. tumescent Lee. — Piceous, clothed with brownish hair. Thorax scarce- 

 ly longer than wide, moderately convex, with punctures moderately densely 

 placed, hind angles not divergent, carinate ; flanks of prothorax beneath densely 

 punctured, a little less densely posteriorly ; prosternal mucro horizontal, meso- 

 sternum moderately prominent. Elytra striate, striae coarsely punctured near 

 the base, more finely toward the tip, intervals convex, punctulate. Length 

 .44 — .66 inch; 11 — 14 mm. 



The two specimens before me by the form of the thorax seem to be 

 females. The thorax has the sides moderately arcuate in front and 

 the disc is slightly broader behind the apex than at base. The whole 

 contour of the species resembles the preceding, but the parallel hind 

 angles and the brownish pubescence seem to warrant its being re- 

 tained as distinct. 



Occurs in California. 



A. oregoniis Lee. — Piceous, elytra luteous, legs varying from pale to 

 piceous, surface sparsely clothed with yellowish pubescence. Thorax not 

 densely nor coarsely punctured, hind angles slightly divergent and with a 

 fine carina rather close to the lateral margin; flanks of thorax beneath rather 

 coarsely but not densely punctured, with a large smooth space posteriorly; 

 prosternal mucro rather strongly flexed, mesosternum inconspicuous. Elytra 

 striate, strife punctured, intervals flat or feebly convex and punctulate. Length 

 .32— .40 inch; S— 10 mm. 



Male. — Thorax distinctly longer than wide, sides nearly straight and gradu- 

 ally convergent in front. 



Female. — Thorax as wide as long, sides rather strongly arcuate in front. 



The differences in form between the two sexes are very sharply 

 marked, the female resembling in outline Cori/mhites rotimdicoUis, 

 while the male has the outline of Sericosomus /usi/ormis. 



Occurs in Oregon and Vancouver. 



