NORTH AMKRICAN COLEOPTERA. 119 



small, ovate, third a little shorter than first, fourth longer than the 

 third, joints five to ten nearly equal in length, shorter than the 

 fourth, but longer than the third, eleventh equal to the fourth. 

 Thorax quadrate, slightly wider than long, sides feebly arcuate, disc 

 not impressed. Elytra oblong-oval, broader in the male; epipleurse 

 wide, extending three-fourths to apex ; prosternum distinctly sepa- 

 rating the coxffi ; anterior coxal cavities open behind. Legs mod- 

 erate in length ; tibise scarcely broader to tip, the outer edge rounded, 

 the apex without spur ; tarsi moderate, first joint of posterior pair 

 longer than the next two ; claws appendiculate. 



This genus was named by Crotch from a pair of specimens in my 

 cabinet and characterized in a few words without any attempt to 

 indicate its relationship beyond that it belongs in the vicinity of 

 Laiperus. Its position is rather difficult to assign, owing to the want 

 of extensive material for comparison. That it is not very near Lu- 

 periis is shown in the shorter first joint of the hind tarsus and the 

 absence of tibial spurs. On the other hand, that tarsal joint is 

 longer than in the groups in which the joint is at most the length 

 of the next two. From a manuscript label still attached to my 

 specimen, it is evident that Crotch was at first disposed to place the 

 species in Malacosoma. There seems no course to be pursued but to 

 place it in a separate group. 



A. fiilvas Crotch, Proc. Acad. 1873, p. 55. — Oblong-oval, subdepressed, above 

 fulvous; bead, auleuua?, legs, meso-metasternum and last ventral segment pice- 

 ous black, surface glabrous, shining. Head smooth, a transverse impressed line 

 between the eyes, frontal tubercles flat, clypeus carinatc. Thorax quadrate, a 

 little wider than long, sides feebly arcuate in front, thence slightly sinuate to 

 base, base regularly arcuate with a marginal line, a little wider than the apex, 

 hind angles rectangular, anterior angles slightly nodiform, disc convex, smooth 

 and not impressed ; scutellum piceous. Elytra oblong-oval, slightly wider be- 

 hind the middle, disc smooth and shining. Body beneath very sparsely pubes- 

 cent. Length .20 ^—.24 9 inch.; 5— 6 mm. 



Male. — -Antennae a little more subserrate than the female; third and fourth 

 ventral segments each with two slender processes on each side of the middle of 

 the posterior margin of the segment, the disc flat. Last ventral deeply concave, 

 smooth, piceous; side margin of elytra deeply and irregularly plicate one-fourth 

 from apex. 



Female. — Ventral segments simple ; elytra simple. 



In the male there is on each elytron a short, indistinct piceous 

 vitta near the apex. 



The male ventral characters are certainly very extraordinary. 

 The structure of the last ventral is not unlike that seen in some 



TEANS. AM. ENT. SOC. XX. JUNE, 1893. 



