NORTH AMKRIUAX COLEOPTERA. «0 



coarsely aud closely punctured, a vague median impression, color dull yellow, 

 with sometimes a median darker line. Thorax usually more than twice as wide 

 as long, although much narrower in the male, wider at base than apex, sides 

 arcuate, or in some males very obtusely subangulate, disc convex, often even 

 more usually with a vague median and lateral depressions, surface variably punc- 

 tate, sometimes sparsely, more usually coarsely and closely; elytra oval with 

 rounded humeri, the apices obtuse, or subtruncate in most females, the lateral 

 margin not explanate, the marginal sulcus not evident, surface very coarsely, 

 deeply and moderately closely punctate, sparsely pubescent, with three narrow 

 piceous vittse on each side, which are often entirely obliterated. Body beneath 

 more finely and closely punctate, finely pubescent, color usually like the upper 

 surface, but the metasternum and abdomen are sometimes piceous. Legs always 

 pale. Length .14 — .26 inch. ; 3.5—6.5 mm. 



MaJe — Last ventral with a narrowly triangular incisure extending half the 

 length of the segment: claws finely bifid close to the tip. 



Female. — Last ventral more broadly triangularly emarginate; claws more 

 deeply bifid and the divisions more divergent, 



111 this species the middle coxte are distinctly separated by a pro- 

 longation of the niesosternuni meeting the metasternum. The hu- 

 meri are also more rounded, the metasternum shorter. The wings 

 seem le.ss feebly developed. 



The variation in this species is carried to such a degree that it is 

 not easy to find two specimens even reasonably alike. In form most 

 of the females are as broadly oval as G. externa, and more convex, 

 while the males are as oblong as any Monoxia. The general color 

 varies but little, although the markings are very variable. Often 

 the thorax shows no traces of the three spots, but they are never 

 very well marked in any specimen. The vittae on the elytra are 

 slender, and when perfectly developed, which is rare, are nearly 

 entire, but all gradations are seen from this to the perfectly plain 

 form. The sculpture of the thorax varies greatly, specimens (always 

 female) occur with the surface sparsely punctate with smooth inter- 

 vals and without inequalities, and from this form they pass gradually 

 to those with coarse and close punctures. The elytral sculpture does 

 not vary so greatly as the thoracic, but extretne forms are quite dif- 

 ferent in appearance. When specimens are fresh or carefully pre- 

 served, the pubescence is always distinct, seeming to be more persistent 

 in the males, the larger pinguid females soon losing the hairs. In 

 those specimens in which the pubescence remains it will be observed 

 to be in great part erect. 



This species seems to be very widely distributed, specimens having 

 been seen from the entire region east of the Rocky Mountains and 

 the Rio Grande, and from Canada to the Gulf 



TKAN.S. AM. ENT. SOC. XX. MAY, 1893. 



