182 NORTH AMERICAN 



equal in length, while in arboricola they are very unequal in length 

 and much more unecjual in thickness. Perhaps the most decisive 

 point of difference is in the sexual characters ; the first and some- 

 times also the second ventral segments in the males of arboricola are 

 ornamented with a transverse series of broad deeply impressed longi- 

 tudinal canaliculations, while in the males of piiua/is tiiere is no trace 

 of tiiis formation, but a mere trace of two very narrow exceedingly 

 feeble distant and partial longitudinal impressions. Tiiere is also a 

 decidetl difference in the nature of the abdominal pubescence, this 

 being much more abundant and finer in arboricola. In color and 

 form the two species differ very greatly, piinalis being relatively 

 longer and narrower, with the sides mucli less arcuate. They also 

 differ greatly in tlie sculpture of the scutellum. 



»ISO-\YCHA Cliev. 



D. pi'OCera n. sp. — Form elongate narrow ; sides parallel. Color of 

 liead lilack, with a dilfused band of fuscous between the antennae, pronotum 

 pale reddish, with narrow paler liavate margins, elytra having a broad 

 sutiiral vitta, a very broad discal one which does not attain tlie apex, and a 

 broad lateral vitta not attaining the reflexed side margins and not attaining 

 the apical angles, all of black, remaining portions bright yellowish-white, 

 and so narrow as to give the appearance of black elytra with narrow silvery 

 vittae ; under surface black, except the prosternum and its side pieces which 

 are pale flavo-testaceous, and the last ventral segment which is fuscous, the 

 remaining segments also have at each side a small diffused patch of dark 

 fuscous ; femora dark rufous, tibiae and tarsi black, antennae intense black 

 throughout; upper surface glabrous, polished, under surface covered some- 

 wliat densely with very short fine and inconspicuous pubescence ; elytral 

 epipleurae black, outer edge pale Havate. Head slightly wider than long, 

 median portions impunctate ; occiput having a very small median imjjres- 

 sion, between which and each eye, there is a large irregular impression 

 containing three or four large punctures, also in the mid'lle of the front 

 between the middle points of the eyes, a small deep impression with four 

 short radiating canaliculations, and between this and each eye a few small 

 scattered punctures ; labrum much wider than long, strongly sinuate ante- 

 riorly; antennae one-half as long as tlie body, covered densely with very 

 fine short pale pubescence, second joint huiger than wide, oval, one-half as 

 long as the tiiird, the latter three-fourths as long as the fourth. Prothorax 

 distinctly more than twice as wide as long ; sides feebly convergent ante- 

 riorly, feebly arcuate ; anterior angles slightly thickened, rounded ; apex 

 transverse, feebly indented near each apical angle ; base broadly arcuate, 

 broadly and feebly trisiuuate, basal angles narrowly rounded, each bearing 

 an erect seta; disk broadly convex, almost imi)unctate, very minutely and 

 feelily reticulate, transparent, not maculate except a vague longitudinal 

 median spot. Elytra at base as wide as the pronotum, widest at two-thirds 



