THE CANADIAN ENTOMOLOGIST. 221 



11a. Labrum much longer than broad. (Fig. 21.) Pronotum and 

 mesonotum chitinized. Metanotum with four plates; two 

 broad medium ones, lying one behind the other (the pos- 

 terior one being hard to distinguish) and two lateral ones, 

 - small and triangular. ^Fig. 22) Odontocerida. 



lib. Labrum much broader than long. (Fig. 20.) Thoracic 

 armature various, but not as above 12. 



12a. *Gula subquadrate, widely separating the pleune. (Figs. 23, 

 24.) Prothorax and mesothorax chitinized dorsally. Meta- 

 thorax membranous. No prosternal horn 13. 



12b. *Gula triangular or elongated. Pleurae contiguous or nearly 

 so at the apex of the gula. (Figs. 25, 26.) Thoracic 

 armature not as in 12a. Prosternal horn generally present. 

 (Fig. 35) 15. 



13a. Long spur-bearing processes on distal ends of first and second 

 tibiae. (Fig. 27.) Hind tibict? divided. (Fig. 28.) Hind 

 claw either long and bristle-like or very short and bearing 

 man\' bristles. (Fig. 29.) Labial lobe with numerous 

 bristles near the middle of the ventral side 

 Molannina (Fam. Molannida.) 



13b. No spur-bearing processes on first and second tibia?, but 

 sometimes a swelling on the first tibiie. (Fig. 32.) Hind 

 tibi.ne not divided except in Mystacides. Claws normal. 

 Few bristles on labial lobe 14. 



14a. Femora not divided into a short apical and a long distal piece. 

 Mandibles with inner bristles, and a clump of accessory 

 bristles near distal end of convex side. (Fig. 39). Chitin 

 points over lateral line on abdominal segments HI to VHL 

 Beraina (Fam. Molannidce) . 



14b. Femora of middle and hind legs divided into a small basal 

 and a long apical piece. (Fig. 3L) Right mandible with- 

 out inner bristles. No accessory bristles on back of 

 mandibles :. Leptoceridce . 



*In two subfamilies the characters will not agree with all those listed in 

 either 12a or 12b. Forms agreeing with r2b in all except the form and position 

 of the gula (Brachycenlrince) or in all except thoracic armature {Sericostomatince) 

 should remain in 12b. 



