144 THE CANADIAN ENTOMOLOGIST. 



fovea ; costal nervure towards apex neither thickened nor clavate, 

 the cubitus originating from the basal nervure ; costal cell with an 

 intercostal vein ; scape of antenna long or rather long. 



Head transverse, the temples not very broad ; third joint of 

 antenna very long, three or four times longer than the long 

 scape ; ovipositor more or less exserted. . . Family V., Xyelidse. 

 Head quadrate, the temples very broad, third joint of antennae 

 rarely much longer than the scape ; abdomen much depressed, 

 the ovipositor hidden Family VI., Lydidse. 



2. Basal nervure in front wings usually uniting with the subcostal vein far 



from the origin of the cubitus ; basal plates of first abdominal 

 segment usually closely united, rarely showing a slight median 

 emargination at apex ; if deeply emarginate, the sides of the 

 abdomen acutely margined, while the antennse are clavate 7. 



Basal nervure in front wings usually uniting with the base of the 

 cubitus or with the subcostal very near its base ; basal plates of 

 first abdominal segment most frequently not united, medially slit or 

 with a wedge-shaped or broadly triangular emargination, sides of 

 abdomen rounded, never acutely margined. 



Front wings with two marginal cells 6. 



Front wings with one marginal cell 3. 



3. Front wings without a lanceolate cell 5. 



Front wings with a lanceolate cell. 



Antennae 9- to 25-jointed 4. 



Antennae 3-jointed. 



Hind wings with an anal cell ; tibiae usually with lateral spurs ; 

 antennjB in $ with the third joint very long, subclavate or 

 filiform, densely hairy, in ^ most frequently 

 forked Family VH., Hylotomidae. 



4. Hind wings with an anal cell; $ antennas usually serrate or sub- 



serrate, $ antennae ramose or biramose. , Family VHI., Lophyridae. 

 Hind wings without an anal cell ; $ antennae most frequently sub- 

 clavate or filiform, S antennae usually ramose or 

 filiform Family IX., Perreyiidae. 



5. Hind wings without an anal cell; antennas 6- to 25-jointed, in ? 



clavate or subclavate, more rarely filiform, in ^ ramose, or simple, 

 filiform, multiarticulate Family X., Pterygophoridae. 



