222 THE CANADIAN ENTOMOLOGIST. 



inward side. Venter not turned upwards behind, horizontal. Middle 

 and hind tibiae straight on the outer side, and the tip truncate. 



" Phlodotrihus Lat. — Antenna with a 5-segmented funicle and a much 



longer fan-shaped club divided into three long leaf-shaped segments. 



Venter arched, notably upturned behind. Middle and hind tibiae rounded 



on the outer margin and toothed." 



In PJilceotribus caiccasicus and in Ph. scai'abceoides the hind tibipe are 

 distinctly rounded and toothed on the outer margin. In PJilceophthoriis 

 rhododaciyhis the tibiae are straight on the outer margin and abruptly 

 truncate distally, with one tooth on the outer margin and a series of teeth 

 distally. In Phlodotribus fj'onialis and Pklceoiribtis limiiiai-is the outer 

 margin of the hind tibiae is strongly rounded and toothed, somewhat as in 

 caucasictis and scarabceoides. In P. picece, n. sp., the hind tibiae are 

 slightly rounded on the outer margin, and broadly rounded on the distal 

 margin, with one tooth on the former and a series of six on the latter. In 

 P. scarabceoides the lateral extension of the segments of the club are very 

 elongate ; in caucasicus distinctly shorter ; in liminaris still shorter; in 

 frontalis shorter than in limijia^'is., and m picece and puberuliis shorter than 

 in frontalis. In P. rhododactylus these lateral extensions are barely 

 noticeable. In these forms there is a distinct gradation in this character, 

 and the difference between the conditions in the clubs of scarabceoides and 

 picea. is quite as decided as that between the latter and rhododactylus. In 

 caucasicus and scarabceoides the antennae are close together on the front 

 above the inner angles of the mandibles. In rhododactylus., limi?iaris, 

 frofitalis dindpicecB the antennae are further apart, arising above the outer 

 angles of the mandibles. In my specimens oi caucasicus and scarabceoides 

 the venter is distinctly bisinuate in profile, with the thorax convex, bending 

 upward to the abdomen. In rhododactylus the venter sometimes exhibits 

 this curve in lesser degree, but is usually nearly horizontal. In liminaris 

 ^nd. frontalis the ventral curve is very feeble but variable, and in picece 

 is scarcely to be detected. 



This intergradation of character leads me to believe that Phloioph- 

 thorus WoU. is hardly more than a subgenus cf Phloeotribus Lat. 



The relations of picece to lijninaris, frontalis and puberulus are 

 indicated in the following key : 



A. Club with the lateral extensions of the segments more than twice as 

 long as their width at the base. 



