82 



EXTERNAL ANATOMY OF INSECTS. 



tl)e two joints thus reposing in parallel lines. The lower Hp 

 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. 

 Raphid'ia displays the three lower parts of the lip in equal 

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

 Next in order come the Maxilla, or 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 distinguished by constantly 

 bearing the maxipalpn, 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 maxillcs 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 affording 

 distinguishing characters. Each feeler-jaw is divisible into 

 four parts, the iiisertio, maxilla or disk, jialpifer,^ and lacinia. 

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



" Maxillam constantissimum invenimus, vix in congeneribus aberrat. — 

 Fabrichis. 



Piece palpijere of Straus-Diirckheim. 



^ Chez les Melolontha le corps de la niachoire est forme de quatre pieces, 

 mobiles les unes sur les autres, mais qui n'ont point encore ete decrites. L'une 

 d'entre elles fixe la machoire sur la basilaire : c'est une piece i peu pres 

 trapezoi'de, portant a son petit cote parallele un condyle articulaire, qui penetre 

 dans la cavite cotyloide interne qu'on remarque sur I'apophyse anterieure de la 

 basilaire. De ce point d'articulation cette premiere piece se porte transversale- 

 ment en dehors, et va s'unir par son bord oppos^ aux autres pieces du corps de 

 la machoire, d'ou je lui donne le nom de Brancke transverse.— La piece Dorsale 

 des machoires est chez tons les coleopteres une plaque presque plane, en triangle 

 isoc6le; elle est unie par son petit cote a. 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 externe. Par son bord interne 

 cette seconde piece s'articule lineairement avec une troisieme, placee a la face 

 inferieure de la machoire, et que je nomme V Inter maxillaire, et son bord externe 



