16 INSECTA. 
destitute of ocelli, is prolonged anteriorly in the manner of a cone 
or point, bearing two filiform antennz, shorter than itself, and 
composed of seven joints at most, the last pointed. Their poste- 
rior legs are large, long, and approximated to the intermediaries, 
which are more than usually remote from the anterior ones. These 
Orthoptera, peculiar to South America, form the subject of an ex- 
cellent Monograph, published by M. Kliig. 
Truxauis, Fab.—Gryllus acrida, Lin. 
The Truxales, by their compressed, prismatic, ensiform antennae, 
and by their pyramidally raised head, are removed from all other’ 
Orthoptera(1). 
Some species of the following subgenus, such as the Gryllus cari- 
natus of Linneus, and the G. gallinaceus of Fabricius, are interme- 
diate, by their antennez, between Truxualis and Acrydium proper, and 
form the genus Xipnicera, Lat.—Pamphagus, Thunb. 
Acrypium proper.—Grytuius, Fab.—Gryllus 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 solid, non-vesicular 
abdomen, and from the Truxales in their ovoid head, and their an- 
“tennz, which are filiform or terminated by a button(2). 
They fly by starts, and to a considerable 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(3), some- 
times unite in incalculable numbers and emigrate, resembling in 
(1) Gryllus nusutus, L.; Ro:s., Insect., U, Gryll. iv, 1, 2. The antenne are 
false; Herbst., Ib., vii, 7, the male; 6, the female; Stoll, viii, b, 27—Drury, Insects, 
hee. Ba le 
(2) 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. Ihave described this organ (Mémoires du Muséum d’Histoire Natu- 
relle, VIIL) which must necessarily have some influence on the stridulous noise of 
these Insects, as well as on their flight. I have compared it toa sort of drum. 
(3) The general reader must not allow himself to be deceived by names. This 
Insect is what we commonly call a Grashopper. The Locust, so called in this 
country, is a totally different Insect, and belongs to another order. See Hemiptera, 
genus Cicada or Teitigonia. Am. Ed. 
