498 



be easily distinguished by the characters given in the following 

 table. Very large numbers of all these species have passed 

 through my hands but I cannot remember to have seen any 

 doubtful specimen, although many have borne no indication of 

 the food plant. No doubt extreme aberrations of some of the 

 species may be found, which might not be distinguished by the 

 table. Owing to the great variability in the size of the indi- 

 viduals, so far as possible the characters of different species 

 should be compared in examples of about equal size, where 

 the characters are comparative. 



Table for Distixgi'ishing Blackburni Group of 



Plagithmysus. 



1 (10) Pubescent lines of the elytra rarely yellow anil wide and in 



that case the antennae have more than the scape red. 



2 (3) Elytra without distinct black or dark fuscous color between 



the furcation formed by the pubescent lines; antennae black, 

 the scape at most sometimes more or less red. 

 (Elytra often entirely pale externally to the pubescent lines, 

 more rarely these are margined with black outwardly; hind 

 femora in one common variety conspicuously red on the 

 apical portion, black in the middle, and unlike any other 

 species in this case) ....••■■ varidns^ 



3 (2) Elytra distinctly black or very dark colored in the furcation; 



antennae often wholly or largely red (sometimes dull, dark 

 red) but in extreme cases only the second joint is of this 

 color. 



4 (7) Hind femora wholly red, sometimes suffused with black, 



apically at the sides, but on the upper side the red extends 

 to the apex. 



5 (6) Basal joints of the antennae with the black, bristly hairs 



long, dense and conspicuous ; usual food plant SopJiora 

 darwinianiis. 



6 (5) Basal antennal joints evidently less setose. (When series are 



placed side by side the present species appears to have the 

 elytra evidently wider at the base than the preceding and its 

 food plant is Pipturus.) lamnrclcianns db. 



7 (4) Hind femora either largely or wholly black except the basal 



stalk, or at least with a considerable portion at the apex 

 entirely black, even on the upper surface. 



