242 Bulletin of Laboratories of Denison University [v^oi. xi. 
tion which contains specimens, with one exception, of all the 
North American species of Panorpa, and also the officers of 
the National Museum for the loan of their collection in the 
family. Dr. E. P. P'elt and Mr. C. C. Adams and others have 
assisted me materially in the loan of specimens. After getting 
this collection together I find that a large part of North Amer- 
ica is represented but more material from our southern states 
would have been desirable. 
The following key is offered for the separation of the genera: 
1. Ocelli present ....... 3 
Ocelli absent . . . . . . . 2 
2. Wings well developed, anntennae short, thick, and nar- 
rowed at the apex. Appendages of the male very long, 
with an articulation near the middle, . Merope. 
Wings of female rudimentary, of male imperfect, antennae 
filiform, ...... Borens. 
3. End of the abdomen in the male developed into the form 
of a chelifer, antennae long and filiform, . . 4 
End of the abdomen in the male not developed into the 
form of a chelifer, abdomen cylindrical, antennae shorter, 
and gradually decreasing in size towards the tips, Bittacus. 
4. Tarsal claws toothed, abdominal segments 7 and 8 modified, 
and elongated, rostrum elongated, . Panorpa, 
Tarsal claws simple, abdominal segments 7 and 8 of the 
male short, similar to the preceding segments, rostrum 
short, triangular, .... Panojpodes. 
Panorpa Linn. 
The species of this genus have four well developed wings, 
which in our species are banded or spotted with dark brown. 
The head is produced downward into a beak, and the mouth 
parts are borne at at the end. The mandibles are slender and 
two-toothed at the apex ; the antennae are only slightly smaller 
at the apex than at the base ; the legs are rather short, and 
each tibia bears two strong spines at the apex of its inner surface. 
The genus was indicated by Linnaeus about 1767 in his 
Systema Naturae. Species which at the present time are 
