444. MR.-A. H. HALIDAY ON IAPYX, 
entire breadth of the segment, a very small interval only remaining between them. On 
the inner side, before the middle, they are armed with a few teeth, and thenceforth finely 
serrated—the attenuated and incurved tips crossing each other when the forceps is 
closed. The forceps, as well as the segment which bears it, is horny and rigid. The 
head, body, forceps, and limbs bear fine scattered hairs of different lengths, which appear 
simple under a lens. "There is no trace apparent, on the under side of the abdomen, of 
such appendages as the genuine Lepismide in general possess, and which are not entirely 
obsolete in Campodea. 
In younger individuals the antennæ are shorter and have fewer joints, and the forceps 
is proportionally smaller. Otherwise they resemble the adult insect. Even one which 
I found, not larger than a Lipura fimetaria, presented all the external characters of its 
kind. But it is very rare to find them less than two lines in length. The body being of 
much firmer consistence than that of Campodea, they burrow in the ground, or insinuate 
themselves into chinks even of solid ground, with extreme agility; and once out of 
sight, it is nearly hopeless to recover them by turning up the soil. They inhabit much 
the same localities as Campodea, under fallen leaves, or stones, or at the roots of trees, 
but are not quite so dependent on the degree of moisture. I presume their nutriment 
to be decaying vegetable matter or minute cryptogams; but from their aversion to light 
it was almost impossible to see the manner of their proceedings, although I kept a 
number of them alive for weeks together. I have observed the use they make of the 
forceps, just like Forficule, and the tactory function of the short labial palpi. 
With regard to the-internal structure, the softness of the parts opposes nearly the 
same difficulties as in the case of the Poduride, and my discoveries among them have. 
been very little. The chief tract of the intestinal canal is occupied by a straight roomy 
cylindrical ventricle, without distinct proventriculus (or gizzard, as in the genuine Lepis- 
mide), or any Malpighian vessels ; the cesophagus is much attenuated for some distance 
before its insertion into the ventricle; the small intestine is comparatively short, and is 
concealed by a conglomerate mass of acini, which, dividing into two arms, envelopes a . 
number of moniliform ovithecee of few (about five) cells, terminated by a short filament, 
which are implanted in the lower part of the two slender, somewhat varicose, deferent 
vessels, nearly as long as the ventricle, and lying at each side of it, and which end ina 
sort of small follicle, scarcely wider than the greatest diameter of the deferent, from 
which it is divided by a stricture. I have not found in any individual examined a dis- 
tinction of the other sex. From this description it will be perceived that the intestinal 
characters agree with those of Campodea as closely as the structure of the oral organs 
and the external form in general, with the striking exception of the forceps so exactly re- 
sembling the analogous organ in the stirps Labidura that it is difficult not to recognize in 
it an indication of natural affinity, which would considerably dislocate the usual arrange- 
ment of the groups of Neuroptera with non-quiescent pupa—the Orthoptera of authors. 
Yet the essential characters of the Labidura are in many respects so remote from those 
of the genus Japyz, that I should deliberate long before attributing to that similarity 
more than a secondary significance. On the other hand, with the reservation of the few 
differences scheduled in the comparative diagnosis of Japyx and Campodea, these two 
