242 THE CANADIAN ENTOMOLOQIBT. 



five irregular pale brown fascise ; pubescence sparse, fine, short, suberect 

 and entirely whitish in colour. Antenna? very strongly serrate {^) or 

 moderately so ( 9 ), the serration beginning with the fourth joint, which is 

 as wide as the fifth; joints 4-10 all much broader and long. Head 

 densely punctate, very feebly impressed. Prothorax one-half wider than 

 long, sides not veiy strongly rounded, apex four-fifths as wide as the base, 

 surface densely, almost cribrately punctate, median impression feeble, 

 lateral basal fovese moderately deep. Elytra barely as wide as the 

 prothorax, sides feebly sinuate basally, gradually narrowed behind, strise 

 impressed, closely, moderately punctate, intervals narrow and more or less 

 convex. Beneath with sparse white recumbent pubescence, prosternum 

 truncate in front ; abdomen rather sparsely, not coarsely, punctate, and 

 polished ; last ventral without apical plate. Length, 7)^-9 mm. 



The type is one of three examples taken by Dr. Fenyes at Mojave, 

 Cal., on Larrea. In one specimen the brown bands are darker and wider, 

 and the elytra might more properly be described as brown, with irregular 

 yellow fascia?. In this species the sexual differences in the antennre are 

 remarkable. Joints 4-10 are not only very broad in the male, but they 

 are very densely minutely punctulate and clothed with an exceedingly 

 short, erect blackish pile. In the female the surface of tlie joints is 

 moderately punctulate and shining, and clothed as usual. By the broad 

 fourth joint of the antennae this species is related to cribricollis, gemma 

 and itisignis. By some mischance, cribricoUis is, in my Synopsis of this 

 genus, erroneously tabulated with those species having the fifth antennal 

 joint abruptly wider than the fourth. The species is really very close to 

 the one here described, but differs in having the elytral markings black 

 instead of brown (perhaps not constant), the punctuation of the ventral 

 segments coarser, especially apically, the last ventral with evident thick 

 marginal crest. Males of cribricoUis are as yet unknown, so it is not 

 possible to say if a similar sexual disparity in the form of the antennae 

 exists. 



Trirhabda labrata. n. sp. — '^oxxsx ?c!\d. %\z^ o\ flavolimbata. Elytra 

 brilliant green, with narrow pale margin, pubescence unusually sparse and 

 short, the surface quite strongly shining, punctuation dense and rather 

 coarse. Prothorax about twice as wide as long, more or less strongly 

 transversely impressed, and with the usual three spots, these being large, 

 sometimes confluent, metallic-green ; surface highly polished and sparsely 



