20(S THE CANADIAN ENTOMOLOGIST. 



It is quite probable, however, that species will yet be discovered in 

 our fauna, especially in the unexplored regions of Alaska and British 

 Columbia. 



The four genera recognized by Konow may be distinguished by the 

 aid of the following table : 



Table of Genera. 

 Flagellum with joints 2-13 of an unequal length, gradually decreasing in 

 length, the middle joints without long, compressed, subfoliaceous 



processes 2. 



Flagellum with joints 2-13 of an equal length, or nearly so, the middle 

 joints with long, compressed, subfoliaceous processes or branches. 

 Process of the first flagellar joint at least as long as the two follow- 

 ing joints united, or longer ; penultimate antennal joint longer 



than the second Rhipidioceros, Konow. 



Process of the first flagellar joint shorter than the two following 

 joints united, usually shorter than the second joint ; penultimate 



antennal joint shorter than the second Megalodontes, Latreille. 



2. Antenn?e at least 20-jointed ; joints 4-9 in §, 3-13 in c? , at apex 

 obliquely truncate and somewhat produced, but with each process 

 compactly united with the following ; the penultimate joint of labial 



palpi shortened, triangular Melanopiis, Konow. 



Antennte 13-14- jointed ; joints from fourth and beyond triangular, 

 almost truncate at apex ; penultimate joint of maxillary and labial 

 palpi triangular, much shorter than the last .... Tristactus, Konow, 



Subfamily II. — Lydin^. 



This subfamily is at once distinguished from the Megalodonthice by 

 always having two parallel, deeply impressed lines on the vertex, and by 

 the distinct intercostal vein in the front wings. 



All of our species, so far discovered, belong in this subfamily, and 

 all of the genera, tabulated below, occur in our fauna, except Caenolyta 

 and Gongylocorisa. 



The genera may be easily distinguished by the aid of the following 



table : 



Table of Genera. 



Claws cleft 3. 



Claws not cleft, but with a small median or subapical tooth. 



Anterior tibiae without a lateral spur before apex 2. 



Anterior tibiae with a lateral spur before apex. 



