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Show 16 INSECTA. d estl• tu t eo f ocelli ' is prolonged antcl'iol'ly in the manner. or a cone or po·m t, bearing two filiform antennre, shor.t er than 1ts. elf, and ed of seven J. oints at most, the last pomted. Thcu· paste-compos · d' · r1· 0r 1e gs are large' long' and approximated to the. mterme 1•a nes, \vhich are more than usually remote from the antel'lor ~nes. 1 hese Orthoptera, peculiar to South America, form the subject of an excellent Monograph, published by M. KlLig. TnuXALis, Fab.-G,.yllus ac1·ida, Lin. The Truxales, by their compressed, prismatic, ensiform antennre, and by their pyramidally raised head, are removed from all othet· OrthopteJ•a( 1). . Some species of the following subgeuus, such a.s :he G1'y~lus Cctrtnatus of Linnreus, and the G. gallinaceus of Fabnci.us, are mterme· diate, by their antennre, between Truxalis and AcrydiUm proper, and form the genus XxPHIOERA, Lat.-Pamphagus, Thunb. AcnYDIUM proper.-GnYLLus, Fab.-G1·yllus locusta, and some G. bulla, Lin. The true Acrydia differ f1·om the Pneumorre in their posterior legs which are longer than the body, and in their solid, non-ves~cular abdomen, and from the Truxales in their ovoid head, and the1r an· tennre which are filiform or terminated by a button(2). Th;y fly by start$, and to a considerable height. . . The wings are frequently very prettily coloured, particularly w1th 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 va1·iety of forms. Certain species, called by travellet·s Migratory Locusts(3), .som.e· times unite in incalculable numbers and emigrate, resembling lD (1) Gryllus nasutus, L.; Rccs., Insect., II, Gryll. iv, 1, 2. The antenn:e are false; Herbst., lb., vii, 7, the male; 6, the female; Stoll, viii, b, 27-Drury, Insects, II, xl, 1. . (2) In many species, on each side, and near the origin of the abdomen, lS • large cavity, closed internally by a very thin membranous diaphrngt~, ~oloured like nacre. I have described this organ (Mcmoires du Museum d'H1st01re ~atu· relle VHI) which must necessarily have some influence on the stridulous n01se of thes~ Insects, ns well as on their flight. I have compared it to a sort of drum. . {3) The general reader must not allow himself to be deceived by names. Th~s Insect is what we commonly call a Gra8ltoppcr. The Locust, so called i? thJs country, is a totally different insect, and belongs to another order. See Jlemzptera, genus Cicada or Tettigonia. .11m. Ed. ORTHO!>TERA. 17 their passage through the ail·, 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 excellent 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 inhabitants 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 .fl. migratorius; Gryllus migratorius, L.; Rres.; Insect. II, Gryll., 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 in a frothy and glutinous flesh-coloured matter, forming a cocoon, which the Insect is said to glue to some 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. a?gyptius, tartaricus, 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 pr·epat•ed and eaten in Barbary, as above described. The natives of Senegal dry another, the body of which is yellow, spotted with black; they then, as I have been told by M. Savigny, reduce it to powder, and employ it as flour. It is figured by Shaw and Denon. These two species and several 'others have a conical projection of the prresternum, and compose my genus AcRYDIUM, properly so called. Of those which do not present this character but have likewise filiform antennre, some are furnished with wings and elytra in both sexes. They belong to the genus which I have named CEniPODA. Of this number are the two following Acrydia of authors, Gryllua atridulua, L.; Rres., lb., XXI, 1, 23. Deep brown or blackish; thorax raised into a carina; ·wings red, with the extremity black. Gry~lus crerulescens, L.; Rres., lb. XXI, 4. Wings blue, somewhat tinged with green, and marked with a black band( 1 ). {1) Add G. biguttulua, Panz., lb., XXXHI, 6;-G. grosaus, lb. 7;-G. pctiestri8, VoL. IV.-C |