TTTE RYER OK A BKETTiK. 11 



terms lij/iihi ;ni(l lahnnii ;ii'<' oCtcii used syiioiiyiiiously. IIowcvoi', in 

 llic (Icscfipl ions wliicli follow, llic term limilji is used lo dcsi^'iiatc 

 tlio piece in t'l-ont of the mentniii henritiii' tlie labial jmlpi. These 

 pjiJpi are nsnally l^-jointcd (in certain Sta|)hylinids 2- or (^veii 4- 

 jointed). The terminal joint is often of the same form as that of 

 the maxillary iialjn, and otters in many cases important cliaraeters 

 used in classitication. Both mentnm and labium form an luuler lip 

 which prevents the food from fallint^' backwards out of the mouth 

 and, with the aid of the maxilltp, pass it forward to be crushed be- 

 tween the mandibles, the two sets of appendages thus acting much 

 as the tongue of vertebrates. 



77? r Eijfs. The eyes of beetles vary greatly in size and shape, 

 and eacli is com]iosed of a large number of facets or simple lenses 

 in each of which a single filament of the optic nerve ends. These 

 lenses also vary nuich in size, aiul the terms "coarsely granulated" 

 and "finely granulated" are used to denote this variation. In the 

 family GyrinidiV and in the genus Ohcrea the eyes are wholly di- 

 vided, two being above and two on the lower surface of the head, 

 thus enabling the beetle to see upward and downward at the same 

 time. In many species of Cerambycida' and other families they 

 are often deeply notclied or emarginate, either in front or on one or 

 the other of the sides. Rarely they are wholly wanting; rarely, 

 also, as in certain Staphylinids, there are one or two simple eyes or 

 single lenses called ocelli located on the back part of the vertex, be- 

 tween the compound ones. 



In the Cicindelida^ and many of the Carabida-, the head bears, 

 in addition to the regular pubescence, rather long, erect seta? or 

 bristle-like hairs, which arise from special punctures located above 

 and close to the inner margin of the eyes. These are known as 

 supraorhifal setce. 



The Anienme. The principal appendages attached to the head 

 are the a)iten)ta\ They vary greatly in form, point of insertion. 

 and number of joints, and these characters are much used in classi- 

 fication. In the true Coleoptera they are inserted in front of or 

 more rarely between the eyes, often under the side margin of the 

 front. In the Rhynchophora they are borne upon some portion of 

 the beak. The number of joints varies from two in AdnDies to 25 

 or 27 in Priomt.'^, the usiml number being 11. The basal joints are 

 usually less pubescent aiul of a firmer texture than the outer ones. 

 In the latter the surface is usually more or less covered with minute 

 pores which increase greatly the sensitive area. In those genera in 



