294 MODERN CLASSIFICATION OF INSECTS. 
place of insertion of the hind legs, which is at the extremity of the 
metasternum.* The true wings are attached at the anterior lateral 
angles of the metathorax: they are of very large size, somewhat 
exceeding a quadrant of a circle; they are rather opake and 
membranous, with the anterior margin incrassated ; and with a very 
few longitudinal veins, some of which are abbreviated, by means of 
which the wings are folded up longitudinally at the sides of the body. 
The legs are of moderate length, and considerable weakness, but the 
coxe of the two anterior pairs are elongated, giving them considerable 
powers of motion. The femora are simple; the tibize not furnished 
with spurs ; and the tarsal joints are furnished beneath with large fleshy 
cushions, without any terminal ungues. In Stylops the last joint is 
deeply notched (fig. 93. 9.), but it is entire in Xenos ( fig. 94. 15.). 
In Elenchus the tarsi are apparently only two-jointed, and in Halicto- 
phagus 3-jointed (fig. 94.8, 9.), whilst in Stylops and Xenos they are 
4-jointed.+ The abdomen is fleshy, soft, and composed apparently of 
eight segments, the last of which is furnished with a complicated anal 
apparatus, consisting of a deflexed corneous flattened narrow lobe, 
and a recurved horny and dilated point (fig. 94. 14. extremity of 
abdomen of Xenos; 94. 10. ditto of Halictophagus). After death 
this part of the body shrinks up; but during life it is swollen, of a 
dirty pale colour, with transverse dark-coloured scaly plates. 
These insects are parasitic, in their early states, in the bodies of 
* Mr. Newman adopts a different view of the parts of the thorax, regarding it 
as constructed on the plan of that of the Diptera, considering the prothorax as very 
slender, the mesothorax as very large, with its scutellum remarkably elongate (or 
the proscutellum K.), and the metathorax as visible on each side of the latter 
(being the femoralia K.). The pseudelytra he considers as analogous to the tippets 
of the Lepidoptera, the large wings as the fore wings, and he mentions “a pair 
of crumpled opaque whitish hind wings, which are somewhat pedunculated, and 
much resemble the hind wings or halteres of Diptera. My friend, Mr. Walker, 
” 
called my attention to these,” which he describes as attached to the part considered 
by him as the metathorax. I do not hesitate in considering that there must be 
some error in the latter observations, as no other author has ever seen any thing 
answering to the last described appendages, which were probably tattered parts of 
the true wings. Jurine regards the proscutellum and femoralia of Kirby as alone 
constituting the metathorax. 
+ Jurine describes the tarsi of X. Rossii (Vesparum f.) as 5-jointed. 
+ Mr. Curtis, in his Observations upon Elenchus, speaks of a male? captured by 
Mr. Dale, and females by Messrs. Haliday and Walker. His figures D. and W. 
probably represent these individuals, but I apprehend that they are all of the same 
sex, namely, males. 
