£8 IIXMENTS or r.XTOMOT.OOY. 



of insects a« tlicv would othcnvise have been. Without, however, be- 

 ^to\ving some Httle attention on these organs, it is impossible to distri^ 

 butc insects into their natural order with any great degree of certainr\'. 

 In the works of Latreilie, Leach, and most other modern writers on 

 Entomology, the essential characters are established chiefly on the pe- 

 culiarities of these organs. 



The ten principal parts of which the Mouth consists are the follow- 

 ing. 



Lacuvm, or Labium, si'PERius, the UpprrLip: a transverse, soft, 

 moveable piece, of a coriaceous or membranaceous nature, known from 

 its situation at the anterior or upper part of the mouth. This part is 

 very distinct in many of the Coleoptcra, and in (ifi/llus, Apis, and some 

 other genera. Linne sometimes confounds the upper lip with the c/y- 

 pt'us or shield of the head ; and similar instances occur in the works 

 of Faijricius. These two parts may be distinguished by one invariable 

 character; the cli/peus is liNcd, and forms a portion of the head; the 

 upi)er lip is moveable, and is placed more forward. 



L.vBRUM, or Labium, iXFERius, the piece which terminates the 

 mouth beneath, and which is sometimes lengthened so as to form the 

 instrument called ligu/a. It is often bifid, and has the posterior pair 

 of feelers placed at the base. 



Manoibul.t., Mandibles: (PL W.Jig. l.d.) two hard pieces, in sub- 

 stance resembling horn,v.-hich are placed one at each side of the mouth, 

 below the upper lip. 'Jlicse have a lateral motion, while the upper 

 and lower lip move up and down, as in other animals. These difter 

 from the mdxilUe, with which they are sometimes confounded, by not 

 having any of tlie palpi or feelers attached to thc^in. In ra])acious in- 

 sects these are longer than in those which perforate wood ; and the lat- 

 ter again have stronger mandibles than insects which feed only on her- 

 bage or leaves. 



Maxilla {PL 10. fig. 1. e.—fig. 2. a. f fie same inagnifwd): two small 

 pieces generally of a somewhat membranaceous consistency, and in 

 figure diiferent from the mandibles. These are commonly indented at 

 the extremity, and nearly all ciliated at the inner edge. 'J'hcy are 

 placed under the mandibles, and above the lower lip ; their motion is la^- 

 teral. In those insects which have more than two pair of tieelers, the pos- 

 terior ones take their origin from the sides of the maxilla-, {jig. 2.b.c.) 



C.'ale.e, S/ticlJs of the Moatf) : two membranaceous appendages, 

 usually of a large size and cylindrical form, placed one on each side, 

 at tlie exterior part of the jaw, and which cover and protect the organs 

 of the mouth conjointly with the lips. The galea: are inserted at the 

 back of the jaws, as is well exemplifitd in tlie Gryllus tribe. 



■ Lig fi,A. This is the j)art considered by many authors as the lower 

 lip: its situation is immediately under the jaws; and it consists of a 

 single piece, which is generally of a soft texttire, often bifid, and, if at- 



