CERAMBYCID/E 249 



preceding; antennae (cf) similar, extending to about apical third 

 of the elytra, rather less stout; prothorax short, much more than 

 twice as wide as long, nearly as in brunneus; elytra four-fifths longer 

 than wide, nearly a third wider than the prothorax, the punctures 

 well separated, usually rather small and feeble, sometimes moder- 

 ately coarse but never so conspicuous as in the preceding forms; 

 hind tarsi very slender, the second joint of the posterior narrowed 

 slightly from apex to base, rather more than twice as long as wide. 

 Length (cf) 21.0-25.0 mm.; width 8.2-9.4 mm - Indiana, Missouri 

 and Kansas. Seven homogeneous examples, the female unknown. 

 [P. debilis Csy., Ann. N. Y. Acad. Sci., VI, 1891, p. 21]. 



debilis Csy. 



The anterior margin of the prothorax is broadly but rather 

 deeply sinuate in townsendi, the sinus very feebly trisinuate as 

 stated by Bates in defining mexicanus, but the hind margin is 

 broadly and feebly arcuate. In aztecus the anterior margin is more 

 feebly sinuate from side to side, as is also the case in curticollis, 

 but the hind margin is very feebly arcuate in the former and rather 

 strongly medially lobed in the latter. All three of these species 

 differ greatly from flohri and mexicanus in the feebler sculpture 

 and in the 15-jointed, not 14- or 13-jointed antennae as described 

 of the latter by Bates, and this Mexican group as a whole differs 

 decisively from the diversus and imbricornis groups in the relatively 

 more abundant females which have also longer antennae, fewer 

 antennal joints, less slender hind tarsi and several other general 

 differential characters. 



Group III. 

 Subgenus Antennalia nov. 



This group is given subgeneric rank, not solely because of the 

 large and very complex, closely imbricated male antennae, which 

 could very well be considered a simple development of the preceding 

 types, but because of the distinctly different structure of the female 

 antennae, the outer joints being transverse and bilaterally sym- 

 metrical. There seems to be but one species, though several forms 

 represented in my collection by the female alone, which may be held 

 to be subspecific for the present though possibly of higher value, 

 are appended. The preceding group is characterized in one way 

 by the relative scarcity of the females, while here this condition is 

 reversed, the male being apparently much rarer than the female, 

 denoting perhaps a difference in life habits of the two groups. 



