VOL. XVIII, pp. 107-110 MARCH 31, 1905 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



NEW GENERA AND SPECIES OF PERLIDAE. 

 BY JAMES G. NEEDHAM. 



I have had in my hands for study for a long time a single 

 adult specimen of a peculiar stone-fly from Ithaca, N. Y., and 

 a number of larvae from the same locality. The imago was 

 taken at light by Professor R. H. Petti tt in June, 1891, and the 

 larvae were collected by Mr. G. H. Jensen in 1898. Some years 

 ago, in working up a key to our genera of stoneflies, Professor 

 Comstock recognized that the adult represents a new genus, and 

 so indicated, on a label in the collection, without applying a 

 name. Recently, in working on a monograph of our North 

 American stoneflies for a New York State Musuem bulletin , I 

 have studied its characters. In both larval and adult stages it 

 is one of the best marked of our genera. I describe it below, 

 reserving more complete description and figures for the forth 

 coming bulletin. 



Peltoperla gen. nov. 



Type. Peltoperla arcuata sp. nov. 



Ocelli two ; prothorax wider than the head, which it partly covers, and 

 with broadly flaring margins at the sides as well as in front. The segments 

 of the palpi increase in length to the tip ; tarsi, with the two basal joints very 

 short, and the third joint very long. Subcosta conjoined with the radius 

 before the cross- vein at the stigma ; apical costal area with numerous cross- 

 veins; radial sector with several branches beyond the cross- vein at the 

 15 PROC. BIOL. Soc. WASH., VOL. XVII, 1905. (107) 



