344 
INSECTA. 
wise, and the cases, always horizontal, are crustaceous. They ex- 
perience a complete metamorphosis. 
In the sixth or the Orthoptera* *, there are six legs; four wings, 
the two superior in the form of cases, and mandibles and jaws for 
mastication, covered at the extremity by a galea; the inferior wings 
are folded in two directions, or sim^jly in their length, and the inner 
margins of the cases, usually coriaceous, are crossed. They only 
experience a semi-metamorphosis. 
In the seventh or the Hemiptera, there are six legs and four wings, 
the two superior in the form of crustaceous cases, with membranous 
extremities, or similar to the inferior, but larger and firmer ; the 
mandibles and jaws are replaced by setae forming a sucker, enclosed in 
a sheath composed of one articulated, cylindrical or conical piece, in 
the form of a rostrum. 
In the eighth or the Neuroptera, there are six legs, four mem- 
branous and naked wings, and mandibles and jaws for mastification ; 
the wings are finely reticulated, and the inferior are usually as large 
as the superior, or more extended in one of their diameters. 
In the ninth or the Hymenoptera, there are six feet, and four 
membranous and naked wings, and mandibles and jaws for mastica- 
tion ; the inferior wings are smaller than the others, and the abdo- 
men of the female is almost always terminated by a terebra or sting. 
In the tenth or the Lepidoptera, there are six legs, four mem- 
branous wings, covered with small coloured scales resembling dust ; 
a horny production in the form of an epaulette, and directed back- 
wards, is inserted before each upper wing, and the jaws are replaced 
by two united tubular filaments, forming a kind of spirally convo- 
luted tongue f. 
of the maxillae of several Insects, in which he has been fortunate enough to detect 
a retractile appendage hitherto unknown. The first is the Cantharis marginafa, Fab., 
whose maxillae, when dried, offer hut one bifid lobe ; if, however, the abdomen and 
thorax of the recent animal he gradually compressed, a soft, elastic, sub-conic body 
is protruded from the cleft of that lobe, more than half its length, and extending 
beyond the palpi ; a second appendage of the same kind, and about half its length, 
projects at right angles from the base of the first, which is directed forwards, both 
are covered with hairs. The second is the Canili. bimaculata, Fab., in which this 
appendage is still more sensibly and easily displayed, protruding by pressure from 
each maxilla in the form of a tapering filament covered with fine hairs, susceptible of 
considerable extension, reaching beyond the middle of the antennae, and consequently 
more than dorrble the length of the maxilla itself. I have verified these facts in this 
last species. The use of these organs in collectiong nourishment from flowers is 
evident. See Trans. Phil. Soc. ut sup. pi. XV, f. i, e, and f. ii, e. — Eng. Ed. 
* De Geer established this order under the name of Dermaptera, improperly 
changed by Olivier to that of Orthoptera. We preserve the latter, however, as na- 
turalists have generally adopted it. 
i' Spiritrompe. See our general observations on the class. The thorax of the 
Lepidoptera has more analogy with that of the Neuroptera than with that of the 
Hymenoptera, the segment which I have called the mediate appearing to form 
