Hagen.] ) 288 [January 22, 
T believe, not so different as to justify the formation of a new genus. 
If such a separation should be made, the different form of the genital 
parts of the male and female would give, perhaps, more suitable char- 
_ acters. I may add, that Mr. R. M’Lachlan had the same opinion con- 
cerning the identity of K. insignis and Pt. regalis. 
VI. Peteronarcys reticulata Burm. 
This species is the only one now known which does not belong to 
the American fauna; it is found in eastern Siberia, Barnaul, Nerts- 
chinsk, Irkutzk, and according to Burmeister also in Hungaria. 
Mr. M’Lachlan has lately given, Ann. Soc. Ent. Belgique, Vol. xv. 
p- 51, a full description and figures of the sexual organs. “The 
species, by the shape of the genital parts of the male, is related to 
P. regalis, by those of the female, to P. californica. 
The following species of the Perlina contained in the collection 
are so much injured, that a determination is nearly impossible. Of 
most of them only wings remain, often only parts even of them, and 
all the important parts for determination are wanting. Some of 
them are undescribed species, and are new to me; but I should be 
unwilling to describe new species from such fragments. 
2. Perla abnormis Newm. Hag. Syn., 17, 1. 
No. 24. Perla immarginata Say. ? Milton, Aug. 1821; June 
15, 1828 ; Randall, Maine ; pupa ? 
There are, besides the nympha skin, four specimens, and one surely 
does not belong here. One specimen (?) has only wings preserved, 
the others have fragments of the body; but it séems probable that 
all three belong to P. abnormis. The description of P. immarginatz 
does not agree with the specimens, but Say’s species is still unknown 
to me. 
The nympha skin seems too small for this species, and differs from 
the skins in my collection. Another nympha skin, Conway, New 
Hampshire, Aug. 10, 1850, belongs perhaps to this species. 
8. Perla isogona Say. ss. (Say’s determ.). 
No. 66. Sutton, Mass. Dr. Smith. 
Only wings of a large species (forewing 25 mm. long) related to 
P. lycorias of my Synopsis.. I know no other specimen. 
4. Perla spec. nov. 
No. 67. Sutton, Mass. Dr. Smith. : ; 
A female, thorax and head wanting. The wings have a faint yel- 
low tinge, the median vein and its branches dark brown; legs yellow, 
