NORTH AMERICAN COLKOFTERA. 213 



und indistinctly punctate, lower half of clypeus more punctate, frontal impres- 

 sion feeble. Thorax about a half wider than long, narrowed in front, apex 

 broadly prolonged over the head, sides broadly arcuate, lateral margin very evi- 

 dent, angles distinctly auriculate,. disc very convex, sparsely, liuely and indis- 

 tinctly punctate. Elytra much broader tlian the thorax, not more than a third 

 longer than wide, sides slightly sinuate behind the humeri, then broadly rounded 

 to apex, disc very convex, striato-punctate, punctures moderately coarse and 

 closely placed, finer toward apex, the strise regular, excepting the two exterior 

 to the .seventh, which are usually irregular, sometimes, however, regular. Body 

 beneath smooth, abdomen sparsely indistinctly punctate. Legs always pale. 

 Length .13— .18 inch. : 3.5 — 4..5 mm. 



This species varies nearly as much as Typ. canellm. Tlie following 

 have been observed : 



a — entirely pale above and beneath. 



b — (typical form) pale, thorax with an indistinct cloud each side, 

 suture of elytra piceous, gradually broader from apex toward base, 

 side margin narrowly black from humerus two-thirds to apex, first 

 ventral segment black. 



c — as in b, but suture less widely black, on each elytron two in- 

 distinct spots placed as in longula. 



d — thorax as in b ; sutural space broad. 



e — thorax black ; sutural black space wider. 



/ — thorax black ; head, humeri and apex of elytra pale. 



g — entirely black above and beneath, except the legs. 



While this species is placed in the series in which the punctures 

 of the two short striae exterior to the seventh are confused, speci- 

 mens occur in which they are comparatively regular. It may, how- 

 ever, be distinguished from any of the following species with den- 

 ticulate femora by the punctures of the short stride in these latter 

 being quite as coarse as those of the other striae and by the head of 

 dubiom being quite smooth, while it is either coarsely punctate or 

 opaque iu the others. 



It is not surprising that Say suspected that this species might be a 

 variety of Cryptoeephulus canellus Fab. ; some of the varieties of both, 

 in form and color, are deceptively alike. 



Occurs in Dacota, Kansas and Texas. 



M. ealirornicuin Crotch, Proc. Acad. 1873, p. 41. — Oblong, pale reddish 

 brown, thorax slightly darker. Antennje entirely pale. Head punctate iu a 

 broad area along the middle, sparsely on the vertex, more clo.scly and coarsely 

 on the clypeus. Tliovax about a third wider than long, narrowed in front, sides 

 moderately arcuate, anterior angles slightly prominent, the posterior broadly 

 rounded, surface finely punctate, sparsely at middle, a little more closely at the 

 sides. Elytra striato-punctate, striae rarely slightly impressed near the base, the 



TRANS. AM. ENT. SOC. XIX. JULY, 1892. 



