426 Mr. Newport on the Anatomy and 
but imperfectly preserved in the dried insect, and iss rage most ca 
overlooked, exist in all the specimens of the different species of Pteronarcys in 
that collection. Branchiz were thus found to be normal structures in the 
imago Pteronarcys, and even to characterize the genus, although they had 
hitherto entirely escaped observation. 
Since the period when I obtained my single specimen, in December 1843, I 
have anxiously awaited the receipt of other examples of the insect preserved 
for dissection; but as I have not yet been so fortunate as to obtain them, and 
as I desire to make known some account of the internal structures of this re- 
markable insect, I have now made an anatomical examination of my speci- 
men, having taken especial care to preserve it as entire as possible, in illus- 
tration of the facts of its anatomy, and in authentication of my account of 
them. | | 
M. Pictet, the most diligent and elaborate of all monographers of the Neu- 
roptera, has regarded the insects of the genus Pteronarcys, Newm.*, as only 
large Perlide +, which have the body strong and elongated, and the wings 
large and supported by numerous and solid reticulations. He has, however, 
very properly, retained the genus as established by Mr. Newman on the struc- 
ture of the wings. But the entire organization of Pteronarcys,—not merely 
those portions of its external anatomy, the branchiz, which were unknown 
to that gentleman when he established the genus, but also the whole of its in- 
ternal conformation, —most fully authorise the separation of Pteronarcys from 
Perla. The peculiarities of the structures I am about to describe prove | 
the correctness of view, and the acuteness of zoological perception and tact, 
which led the naturalist just mentioned, although entirely unacquainted with 
the anatomy of some of the primary and really important organs of the insect, 
—the peculiarities of Which, doubtless, are of first importance in the life and 
habits of the species,—to establish his genus on characters which then were 
the most obvious for zoological description, although of only secondary phy- 
siological consequence,—the reticulations of the wings. 
To understand rightly the nature of the peculiarities of this insect, I must 
* Entomological Magazine, vol. v. p. 175. 
t Histoire naturelle générale et particulière des Insectes Neuroptéres. - Première Monographie, 
Famille des Perlides, Genéve, 1841, p. 196. 
