THE CANADIAN ENTOMOLOGIST 



39 



Table Showing Principal Characters For The Families of The Order 



Perlaria. 



*In Perlid^e not as elongated as in Capniidae and Nemouridae. 



tin PerlidtC, 1 and 2 very short, 3 greatly elongated; in Capniidae and Nemouridae, either 

 1 or 2 elongated. 



tin Leptoperlidae secondary gills are developed as an anal rosette; in some Pteronarcidae, 

 Perlidae and Nemouridae, secondary gill-tufts are developed in various positions on the thorax 

 or base of abdomen. 



§In the table, I have net included the character of the pres3nce or absence of fusion of 

 M..,+ 4 with Cu,, or Cu,a, in hindwing, as I have been unable to study, the tracheation of larval 

 wings in all families. It should be noted that this fusion is absent in Eustheniida;, but present 

 in both Austrcperlidee and Leptoperlidae. 



