MOl'TII AND MOl'TJI PARTS OK A I'.l'.KTl.E. » 



OflciiliiiH's. ;m<l csix's-iiilly in tlic mcjilcr miiiihcr of Hhyticlio- 

 pliora oi- siioul Itcrllcs (iiol iiicliHlctI in lliis paper), tln' Cront is 

 pi-oloii.uvd so lli.-it the (listniKc between llie cncs jiikI inoutli piirls is 

 greater in leiigtli 1li;iii the rest ol' the liead. Tliis prolonj^-ed por- 

 tion is called the rcslnim or hi'!ih\ and it usually has on each outer 

 side a pToove or sei-ol)e. varyinu' nnirh in leiiiith and used for the 

 recei>fion ol' Ihe louiz' basal joints of the antt'uiue when in repose. 



In most beetles the front is shoi't and the portion in front of the 

 suture is called the chjpcKs. This varies much in form and size. 

 l)eintz' somelimes prolonged so as to extend over the mouth. When 

 small it is by some authors called the rpislonia. Its form, texture 

 and the character of its front margin, whether' dentate, sinuate, 

 tnuicate, etc., are nnieh used in classification, especially in the fam- 

 ily Scaraba'ida\ 



The under surface of the head in front is variably (>xcavated to 

 form the mouth. The parts beneath the eyes and belli n,d the man- 

 dibles forming the side borders of the mouth are the gciia' or cheeks, 

 From the opening of the mouth two seams or sutures may usually 

 be observed running backwards. These are the f/ula)' sutufcs, and 

 they often converge at middle but separate at either end. 



TJif Moufh (1)1(1 Month Parts, In front of or below the clypens 

 and above the mouth there is usually a small movable flap, called 

 the lah'uni or upper lijx It is variable in form, is .ioined to the 

 clypens and is sometimes almost or completely hidden by the latter. 

 In the ma.i'ority of Rhynchophora the labrnm is entirely wanting. 



Inunediately lielow th(^ labrnm are the .jaws or HUindilite^;. They 

 also vary nnich in sliape and size but are usually curved, often 

 toothed on the inner side. and. in ( ertain males, especially those of 

 the Lucanidie. are long and often liear prongs, thus resembling 

 somewhat the antlers of a deer. In a number of genera, as those of 

 some Carabida% the mandibles have a groove or scrobe on the outer 

 side, and this often hears a large puncture from which arises an 

 erect seta or bristle-like hair. The mandibles of beetles are so 

 formed and attached to the epicranium as to move only in- and out 

 or to and from a median line. The>' are used for prehending, cut- 

 ting, tearing and crushing the food; also often for defense, and 

 rarely as clasping organs. Their range of action is often increased 

 by movements of the eiiHn^ head, which are permittcMl bv the loose 

 union of the head and thorax. 



Attached to the sides of the head just below oi" behind the man- 

 dibles is a pair of aiding or accessory .jaws called nxi.ritln'. Each 



