246 the canadian entomologist 



Imagos. 



ff. The intercalaries between the first and second anal veins 



represented by a series of veinlets, often sinuous or forking, 



extending directly from the first anal to the wing margin 



(except in Siphloplecton) ; costal angulation of hind wing 



close to the base ; but two well developed caudal setie, the 



median one being rudimentary or wanting; basal joint of 



hind tarsi evident but not well developed. 



g. Median caudal seta a distinctly segmented rudiment; 



forceps of male three-jointed; posterior prolongation 



of sternum of ninth segment of abdomen of female 



bifid at tip. 



h. Basal segment of fore tarsus of male shortest; 



claws of each tarsus unlike each to each; hind 



wing with the costal angulation acute, and the 



fork of the median vein occupying two-thirds 



the length of that vein Colohiirus^ 



hh. Basal segment of fore tarsus of male longest; 

 claws of each tarsus alike, hind wing with 

 costal angulation obtuse, and the median vein 

 forked' through one-third its 



length Chirotenetes 



gg. Median caudal seta more rudimentary or wanting; fore- 



ceps of the male distinctly four-jointed ; sternum of the 



ninth abdominal segment not prolonged, or if so, 



entire at tip. 



h. Cubitus 2 with a very pronounced curve at its 



base Siphloplectoji. 



hh. Cubitus 2 without such pronounced curve at its 

 base. 



i. Segments 5-9 of abdomen with very broad 

 lateral expansions (onisciform) ; mid- 

 ventral, meso- and metathoracic 



spines Siphlonisca. 



ii. Segments 5-9 of abdomen without such 

 broad expansions and thorax without 

 ventral spines. 



