Canailiiin mntamolajjbt. 



Vol. XXXIX. 



LONDON, OCTOBER, 1907. 



No. 10. 



A LIST OF PERLID.-E FROM BRITISH COLUMBIA AND 



ALBERTA. 



BY NATHAN BANKS, EAST FALLS CHURCH, VA. 



Recently Prof. Raymond Osburn, of Columbia University, New York, 

 turned over to me a large collection of Perlidse made in British Columbia 

 and Alberta. He spent two summers in this region, but collected chiefly 

 in British Columbia. As the lot contains at least a fair proportion of the 

 Perlid fauna of that region, I have made it the basis of a paper. I have 

 also received some Stoneflies of this region from the Rev. G. W. Taylor 

 and Prof. Harvey. In 1903 Mr. R. P. Currie (with Dr. Dyar and Mr. 

 Caudell) spent a season at Kaslo, B. C. He has kindly permitted me to 

 examine his catch of Perlidte (about 100 specimens), which is now in the 

 National Museum ; and I have added his localities to the species in this 

 list. All uncredited localities are from the collection of Prof Osburn. 



As most of the genera are readily separated, I have prepared a key 

 to enable the collector to recognize them. The identification of species is 

 a more difficult matter, and must be made, at present, by a specialist. 

 LTndoubtedly there are other species to be found in this region, but the 

 genera are probably all represented in the list. 



Perlidte, like Lepidoptera, should be spread, at least partly, before 

 identification. The essential specific characters are in the genitalia, but 

 the size and markings of head and pronotum are quite constant in each 

 form. « 



Five of the species are new, the most interesting being the new 

 Fterotiarcys. 



Key to Genera. 



1. In the hind tarsi the apical joint is at least a little longer than the two 



other joints together; anal setje always distinct; the anal cell of fore 



wings usually gives off at least two veins from below . . 2. 



In the hind tarsi the apical joint is at least a little shorter than the two 

 other joints taken together ; sette often absent ; the anal cell of fore 

 wings never gives off but one vein from below 10. 



2. Anterior coxae approximate ; a series of cross-veins in anal region of 



fore wings (Pteronarcini) Pteronarcys. 



Anterior coxae widely separate ; rarely a series of cross-veins in anal 

 region of fore wings (Perlini) 3. 



