ENTOMOLOGICAL SOCIETY 



ever since autumn entomologists all over Europe had been 

 hunting for Calosoma to send to America. Up to the present 

 time, however, not a single specimen had been found. 



Doctor Hopkins said that this effort to introduce parasites 

 of the gypy moth and brown-tail moth was a most important 

 one, and he thought it would be well to endeavor to introduce 

 the parasites of other defoliating caterpillars also. 



Mr. Banks then presented the following paper : 



NOTES ON PTERONARCYS, A GENUS OF PERLID^. 

 By NATHAN BANKS. 



The genus Pteronarcys comprises the largest of our Perlidae. 

 Its members have long attracted attention, since the adult in 

 sects retain, in a more or less perfect condition, the gills which 

 served them as organs of respiration during their early stages 

 in the water. A similar condition, however, is now known to 

 exist in various other stone-flies. All but one of the six or 

 seven described species of this genus occur in the United 

 States, the single exception being from Siberia. The best 

 characters for the separation of the species lie in the structure 

 of the ninth ventral segment in the male, and of the eighth 

 ventral segment in the female. Lately I had an opportunity 

 of examining the collection of the late Doctor Hagen in the 

 Museum of Comparative Zoology, Cambridge, Mass., and 

 now, in going over my own collection, I find that I have a new 

 species, the most distinct one in th& genus. It may be described 

 as follows: 



Pteronarcys spinosa, n. sp. 



Black, scars of head reddish, a narrow reddish stripe on middle of 

 pronotum, ventral segments of abdomen margined with yellowish. 

 Wings not very long ; venation dark brown, 

 fe> <<\ rather dense ; a dark cloud over the first cross- 



vein between the radial sector and the radius, 

 and extending up into the costal area ; another 

 dark cloud near middle of wing and basad of the 

 first one; hind wings with the costal spot, but 

 FIG. i.-Pteronarcys without the i nte rior one; an elongate black spot 

 spinosa: Eighth ven- & . r 



tral plate of female. near basal costa l P art of forewmgs. Female 

 with the 8th ventral segment evenly rounded, 



and with two long, divaricate, spine-like processes from the middle 

 (fig. i). Male with the gth ventral segment broadly truncate at tip, not 



