THE CANADIAN ENTOMOLOGIST. 409 



I have recently received a typical example of Axion plagiatum from 

 Piiebla, Alex., and am in position to prove that Texa?ium, Lee, is a distinct 

 species, differing, among other characters, in that in cacti the two elytral 

 spots are separated across the dorsal surface by only about half the distance 

 that separates them in Texa?m/n, due allowance being made for sexual 

 differences. Alittaceiim is smaller; narrower and more compressed than 

 Texanum, and is probably specifically different ; pleurale is also in all 

 probability a distinct species and not a variety, as stated by Leng ; at any 

 rate, it would be a subspecies of the ixwt plagiatum and not of Texamim. 



Exochomtis^ Redt. 

 Bninius, " Weise " (Leng). 

 Mr. Leng divides this genus into three named subgenera, of which 

 the first, Arawa?ia^ founded upon Arizonicus, is probably a distinct 

 genus and not a subgenus, as it differs in important structural characters 

 as well as in the entire scheme of coloration, which is almost as important. 

 As to Brujnus, " Weise," I am uncertain whether he means Brumus, 

 Muls., or not. In his Brumiis there apparently should be no acutely 

 angulate quadrate ungual tooth, as in typical Exochomtis^ but there is 

 always either a pronounced basal swelling or bulbosity, as in parvicollis^ 

 or a rapid thickening of the claw as in Hogei, or an almost completely 

 simple form as in septe?itrio?iis, with the strong probability, when we 

 consider the absolutely similar or correlative scheme of ornamentation and 

 the identical facies, that there are intermediate forms. I therefore still 

 hold that there is but a single genu?, and that Brumus, " Weise " (Leng) 

 would be a complete synonym of Exochotnus, if there were no other 

 distinction than that of the dentition of the tarsal claws. The case is 

 parallel to that of Oxy?iychus, Lee, and Hyperaspis. But to show how 

 very uncertain the boundaries of Exochomus and Brunms, Weise, become, 

 when based solely on dentition, it may be stated that in cethiops. Bland, 

 the tooth is perfectly distinct and sharply angulate, as usual in Exochomus, 

 though rather less elevated, but this species is placed by Weise and more 

 reluctantly by Leng in Brumus and not in Exochomus. Siibrotundus has 

 tarsal claws nearly as in marginipennis, but with the apical part less 

 abruptly deflexed and, as the ornamentation in Exochomus is not highly 

 variable, as assumed, but on the contrary noticeably constant and per- 

 sistent, I have no doubt that subroiundus is a valid species, and this is 

 confirmed by its very small size and almost circular form. To compare it 

 vf'wh/asciatiis, with its much more elongate-oval form and different colour 



