2a 



EXTERNAL ANATOMY OF INSECTS. 



tlie two joints thus reposing in parallel lines. The lower lip 

 is the organ with which this ferocious larva seizes its prey. 

 The perfect dragon-fly has also a singular development of the 

 labial feelers : the lip itself is however little different from 

 that of Lepidoptera; but the broad mandibuliform feelers 

 are evidently used as organs of prehension and detention of 

 their living prey, as I have often observed on feeding these in- 

 satiable creatures with flies whilst holding them by the wings. 

 Raphidia displays the three lower parts of the lip in equal 

 development; the ligiila is concealed behind the feeler-bearer. 

 Next in order come the Maxillae, ov feeler-jaws ; they 

 are situated in the lower part of the mouth, one on each side, 

 immediately above the lower lip, and below the mandibles, 

 from which they may be instantly distinguislied by constantly 

 bearing the maxipalpi, or maxillary feelers. This distinction 

 is so evident and unvarying, that I hope I shall be pardoned 

 for applying to them the term, feeler-jaws ; a term rather 

 uncouth, I admit, yet I think also very distinctive and descrip- 

 tive. The word maxillce appears to offer no other translation 

 than simply jaws, which would not sufficiently distinguish 

 these organs from the mandibles. The feeler-jaws are less 

 liable to variation than any other part of the mouth." Their 

 variations are therefore most important. Fabricius, Latreille, 

 MacLeay, &c., have borne testimony to their value in aflfording 

 distinguishing characters. Each feeler-jaw is divisible into 

 four parts, the insertio, maxilla or disk, palpifer,^ and lacinia. 

 Straus-Diirckheim has the merit of first distinguishing these." 



• Maxillam constantissimum invenimus, vix in congeneribus aberrat. — 

 Fabricius. 



Piice palpi/ire of Straus-Diirckheim. 



» Chez les Melolontim le corps tie la mfichoire est form6 de quatre pieces, 

 mobiles les unes sur les autres, mais qui n'ont point encore it& dicrites. L'une 

 d'entre elles fixe la machoire sur la basilaire : c'est une piice 4 peu pr^s 

 trapezoVde, portant h son petit cot6 parall^le un condyle articulaire, qui pfeniitre 

 dans la cavitc cotyloide interne qu'on remarque sur I'apophyse ant6rieure dc la 

 basilaire. De ce point d'articulation cette premii^re piice se porte transversalc- 

 inent en dehors, et va s'unir par son bord oppose aux autres pieces du corps de 

 la machoire, d'ott je lui donne le nom de Branche transverse.— La pidce Dorsale 

 des machoires est chcz tous les colioptfires une plaque presque plane, en triangle 

 isocile i elle est unie par son petit cote Ix la branche transverse, et de cette arti- 

 culation elle se porte en avant et determine la direction de la partie principale 

 du corps de la machoire, dont elle occupe la face externc. Par son bord interne 

 cette seconde piice s'articulc linfeairenient avec une troisiime, placec i la face 

 inC6rieure de la machoire, et que je nomme Y Intermaxillaire, et son bord extcrne 



