136 MISS STAVELEY ON THE NEURATION 
the Museum collection, though I do not find it mentioned in the descriptions of that author. 
I may also observe that it is not represented in any of the 370 very much enlarged draw- 
ings of the species of this genus engraved in Koch's ( die Pflanzenlause, Aphiden, getreu 
nach dem Leben abgeleitet und beschrieben. ' Nor are they mentioned in the work of 
MM. Amyot and Serville, ' Hist. Nat., Hemipteres,' Paris, 1843. 
The wing of Aphis is figured with a group of hooks, in a paper by Mr. John Tyrrell, in 
the * Journal of Microscopical Science,' vol. iii. p. 230. This does not agree with any- 
thing that I have seen, nor does his third figure, which represents the fore and hind 
wings ^joined casta to costa. 
In all the species of Aphides that I have examined, there is only a single hook placed 
near the middle of the front edge of the hinder wing ; and the hinder edge of the front 
wing is turned up for a considerable distance to receive it. 
In general the hook is simple, subcylindrical, tapering to a point, with an enlarged 
base ; but in one or two species it looks as if it were compressed or flattened, and is 
slightly striated longitudinally. 
It is not to be observed in the wings oiLivia, Psyllce, or any of the neighbouring genera 
Homoptera which have come under my observation. In most of the other genera of this 
order of insects, the fore wings are more coriaceous or horny than in Aphis, and are to be 
regarded as much in the light of covers to the other wings as organs of flight. 
In some Lepidopterous insects there is an appendage thus described by Mr.Westwood : 
" Another peculiarity consists in the apparatus by which the two wings on the same side 
are retained together in the same line during flight, composed of a loop in which a strong 
bristle plays (fig. 102. 8). The loop is formed either by an elevated portion of the mem- 
brane of the strong central vein of the upper wing on its under surface, or by a tuft of 
raised hairs. This appears to have been first noticed by De Geer (torn. i. tab. 10. f 4) and 
Harris (in his Essay upon the membrane of the wings), and afterwards by Giorna (Lin. 
Trans., vol. i. p. 135) in greater detail. M. Poey (Ann. Soc. Ent. Prance, torn, i.) has 
observed that the bristle is simple in the males but multiplied in the other sex, in which, 
according to Kirby and Spence, there is no annulus, and consequently these individuals 
are less fitted for flight. See also Hoeven in Perussac's Bui. Sci. Nat., March, 1828. It 
is chiefly among the Spingidce and Moths that we find this apparatus, the butterflies being 
destitute of it." (< Modern Class, of Insects,' vol. ii. p. 317.) And he adds as a foot-note 
at page 332 : " Prom the observation of Mr. Haworth (Lep. Brit. p. 19) upon the strong 
flight of the males of the Purple Emperor {Apatura Iris), it would appear that the males 
of that species possess this socket and spring, as he terms this apparatus, and of which 
the females, which fly but little, are destitute." 
represent the hook on the wing in any, although his figures of A. platanoides and A. piniphila are of a large size. He 
has observed and figured the hooks on the hind wing of the genus Chermes in two species, mz., Chermes coccineus 
(t. 12. f. l.o. 9), Chermes laricis (t. 13. f. 5). 
€( 
Mr. Curtis, in vol. xi. of the • British Entomology/ divides the Aphides into two genera, and figures as the types 
Cynara roboris (p. 576), Aphis tilice (p. 577)- He does not describe the hooks in his generic characters, nor represent 
them in his figures : this is the more remarkable, as he figures the hind and fore wings of Cynara roboris in the rela- 
tive position, of an enlarged size, to show the nerves/ 5 
