10 OOLEOPTEKA OF INDIANA. 



one consists of two basal pieces and three outer parts. The first or 

 lower one of the former is called the carclo, and is 

 used to hinge the other parts of the maxilla 1 to the 

 head. The second, the stipes, is jointed to the 

 ardo usually at a more or less acute angle, and 

 forms a place of support for the outer parts. These 

 consist of two lobes and one maxillary palpus. The 

 lobes vary much in form and sometimes one or the 

 other is so small as to be indistinct, The outer one, 

 ol the f/fih a. is often slender and divided into two 

 (After Smith.) jriiits like a palpus. The inner lobe, known as the 

 Jdciitin, is more or less jaw-like and its inner margin is armed with 

 flexible or stiff bristles, spines or teeth which are variable in form 

 and often used as brushes by pollen-eating beetles. The nin.riU<tri/ 

 IKI! ints (plural i><il/>i] arises from an upper segment of the stipes, 

 called the pdlpifcr. The palpi are usually 4-jointed, rarely 3- 

 jointed (in the genus Alcocliara alone 5-jointed). The joints vary 

 greatly in size and form and are therefore much used in classifica- 

 tion. The fourth one is most variable, sometimes being broad and 

 oval or subquadrate, more often triangular or hatchet-shaped. 

 When suddenly narrowed and more slender than the preceding, the 

 palpi are said to be subulate or awl-shaped. The development and 

 shape of the maxilla' of beetles, as of other insects, depend very 

 largely upon the nature of the food, as tho.se organs serve not only 

 to seize and hold the food in the mouth, but also as accessory jaws, 

 aiding the mandibles in rendering the food more suitable for swal- 

 lowing. Their palpi are not only organs of touch, but in many 

 cases act as hands in prehending and carrying morsels of food to thi 

 month. 



The floor of the mouth beneath and between the maxi !,' is 

 formed of two small pie; es called the nicuhun and the labnun. 

 mentum is joined to the </nla or throat, which is the region behuid 

 or below the mouth, the suture between them being the nit iilui .;\i- 

 1ur<\ The mentum varies greatly in form and size and is 'Ten 

 notched er emarginate in front, with a touch at the middle of the 

 cmargination. When deeply notched the side-pieces are cnlied Ic'ties 

 The hibium is usually in front of the mentum or in in" notch 

 between the lobes; rarely it is almost entirely hidden. It Is com- 

 posed of three parts, a central piece, the liyitla, and two side-pieces 

 called the /Hinifjlossci. The labium is often wholly horn-like in tex- 

 ture, in which case the paraglossa are not distinct. In such i ,-ise the 



