MR. J. 0. WESTWOOD ON NYCTERIBIA. 283 
contracted behind the basal articulation. Its coriaceous part in Colonel Sykes’s in- 
sects is covered, both above and beneath, with minute shining black tubercles, four of 
which, on the centre of the abdomen, are of a larger size, and occupy a small naked 
portion. It is, moreover, densely clothed, on the upper side only, from about one third 
of the distance from the extremity to the tip, with long and strong dark reddish bristles, 
each arising from a similar tubercle: at each side above, between the basal corneous 
articulation and the setose terminal portion, three circular spiracles are to be observed. 
Another spiracle of a similar size exists on each side in the midst of the bristly region, 
and a pair more minute near the anus: thus at least five pairs of abdominal spiracles 
exist, although no traces of articulation are visible. It is to be observed, however, 
that the tubercles, in two or three places, are arranged in transverse lines, so as to 
give the appearance of indication of segments : these lines, however, do not appear to 
correspond with the spiracles. 
The anus is situated at the extremity of the body. It is circular, slightly protruded, 
and consists of two lateral horny lunate plates, behind which a smaller circular space 
is observable, with a smaller and more distant pair of corneous flattened plates. 
Such is the organization of the abdomen of the female: and in order to remove any 
doubts which might remain as to the identity of the sex, I shall now proceed to notice 
the nature of the transformations which the insects undergo. No direct statement 
derived from actual observation has hitherto been made upon this subject. Some 
authors have, indeed, correctly surmised, from their evident connexion with the Hippo- 
boscide, that they were pupiparous ; but Latreille regarded them as differing from that 
family in this respect, ‘il paroit cependant qu’elle ne subit pas de métamorphoses, 
qu’elle croit 4 la maniére des poux, des araignées, ayant trouvé en méme tems, sur une 
chauve-souris, des individus de cet insecte trés-petits et peu agés”!; an opinion which 
he expressed in several of his subsequent works. Anxious to ascertain the correctness 
of this supposition, I selected the specimen whose abdomen was most distended ; and 
on making an aperture on its under side, I extracted without difficulty a hard organized 
mass, of a white colour and nearly as large as the abdomen itself, of an oval form, con- 
vex above and flattened beneath, with the broadest extremity offering three small cir- 
cular spots placed in a triangle, with two smaller ones placed at a greater distance from 
them : the sides of the body also exhibited the traces of five articulations. That this was 
the young of the Nycteribia in its pupa state, similar to that of the Hippoboscide, cannot 
be doubted. I regret that it was not in a sufficiently forward state of organization to 
allow of my opening it, with the view of extracting the inclosed Nycteribia. 
Bearing in mind, therefore, that in the only individuals of the genus whose sex has 
thus been ascertained, the abdomen of the female is distinguished by the want of articu- 
' Hist. Nat., tom. xiy. p. 401. 
VOL. I. 2P 
