156 INSECTA. 
Some species of the following subgenus, such as the Gryllus cart- 
natus of Linneus, and the G. gallinaceus of Fabricius, are interme- 
diate, by their antennze, between Truxalis and Acrydium proper, and 
form the genus Xipnicera, Lat. —Pamphaqus, Thunb. 
Acrypium proper.—Gry.iius, Fab.—Gryiivs Locusta, and some 
G. BuLLA, Lin. 
The true Acrydia differ from the Pneumorz in their posterior 
legs, which are longer than the body, and in their sulid, non-vesicular 
abdomen, and from the Truxales in their oveid head, and their an- 
tenn, which are filiform or terminated by a button *. 
They fly by starts, and to a conside1 ‘able height. 
The wings are frequently very prettily coloured, particularly with 
red and blue, as observed in several species that inhabit France. 
The thorax, in some of those that are foreign to Europe, frequently 
exhibits crests and large warts, in a word, a singular variety of 
forms. 
Certain species, called by travellers Migratory Locusts, sometimes 
unite in incalcnlable numbers and emigrate, resembling, in their pas- 
sage through the air, a thick and heavy cloud; wherever they alight 
all signs of vegetation quickly disappear, and a desert is speedily 
created. Their death frequently forms another scourge, as the air 
becomes poisoned by the frightful mass of their decomposing bodies. 
M. Miot, in his exce sllent translation of Herodotus, has given it as 
his opinion, that the heaps of bodies of winged Serpents which that 
historian states he saw in Egypt, were nothing more than masses of 
this species of Acrydium. In this I perfectly agree with him. 
These Insects are eaten in various parts of Africa, where the in- 
habitants collect them for their own use and for commerce. They 
take away their elytra and wings and preserve them in brine. 
A considerable part of Europe is frequently devastated by the 
A. migratorius; Gryllus migratorius, l.; Roes.; Insect, II, 
Gryl., xxiv. Length two inches and a half; usually green, with 
obscure spots ; elytra light brown spotted with black; a low crest 
on the thorax. The eggs are enveloped ina frothy and glutinous 
flesh-coloured matter, forming a cocoon, which the Insect is said 
to glue tosome plant. Common in Poland. 
The south of Europe, Barbary, Egypt, &c., are frequently 
devastated in like manner by other species, some of which are 
rather larger—G. egyptius, turtaricus, L.,—which differ but 
little from the Gryllus lineolus of Fabricius, found in the south 
of France—Herbst., Archiv. Insect., LIV, 2,—a species proper 
to the same countries, and which is the one that is prepared 
Herbst., Ib., vii, 7, the male; 6, the female; Stoll, viii, b. 27—Drury, Insects, II, 
dy ite 
* In many species, on each side, and near the origin of the abdomen, is a large 
cavity, closed internally by a very thin membranous diaphragm, coloured like nacre. 
I have described this organ (Mémoires du Muséum d’Histoire Naturelle, VIII), 
which must necessarily have some influence on the stridulous noise of these Insects, © 
as well as on their flight. I haye compared it to a sort of drum, 
