82 THE CANADIAN ENTOMOLOGIST. 



males are known (Figs. 5, 8 and 11) the 9th abdominal segment is 

 prolonged on the mid-dorsal line; its mid-\-entral callosity is ele- 

 vated on a clavate pedicel; the supra-anal is ru(limentar> , and the 

 subanal plates are developed as a pair of upcurving hooks, whose 

 tips meet the prolongation of the tergiim of the 9th segment. 



These differences are so remarkable that in any other order 

 of insects they would doubtless be used to distinguish genera; 

 but here they appear not to be accompanied by corresponding 

 dirte ence^ in other parts and . e must agree with Enderlein that 

 the remarkable differences in secondary sL'xual characters often 

 found in a series of species of Pljcoptera, otherwise uniform, arc 

 probably not of generic significance. 



There are slight venational differences between species, in 

 the numi)er of cross-veins in certain areas, and in the number of 

 terminal forks of veins Rs and Cu, ])ut in absence of a considerable 

 series of specimens, we have n«^ means of knowing how constant 

 are the apparent differences, and our experience with such characters 

 in this order leave us little confidence in their reliabilit\-. Peltoperla 

 brevis appears, however, to be the only species in which the radial 

 sector- is but once forked beyond the cord. The differences in the 

 form of the apex of the 8th \entral segment in the female is prob- 

 al)ly the most available criterion of the remaining species. Pelto- 

 perla anna is the only species which shows no appreciable prolonga- 

 tion of the apex of this sternite: P. dorcthea, P. ada and P. arcuala 

 have it successixely more prolonged and entire; P. maria, P 

 Cornelia and P cora have it successively prolonged and with a 

 wide median notch. 



The two species hitherto made known are not here redescribed 

 but new figures of them are given in the accompanying plate. 



Description of New Si ecies 

 Peltoperla maria, n. sp. 



Lejigth of female 10 mm.; expands 27 mm. 



Colour brownish, darker on the sides of the thorax and apex 

 of the abdomen Head yellowish with a diffused brownish blotch 

 (Ml the disc in front of the ocelli. Antenn.e yellowish, paler for a 

 distance Leyond the two basal segments, which are thick and 

 brownish. Wings yellow hyaline with brownish \eins. 



