28 ELEMtNTS or ENTOMOLOGY. 



of insects as they would otherwise liave hcen. AVithout, however, be- 

 stowing some Uttle attention on these organs, it is impossible to distri- 

 bute insects into tlieir natural order with any great degree of certainty. 

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

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

 culiarities of these organs. 



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

 ing. 



Labrum, or Labium, supekius, the Upper Lip: a transverse, soft, 

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

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

 very distinct in many of the Coleopteru, and in Gri/tlus, Apis, and some 

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

 peus or shield of the head; and similar instances occur in the works 

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

 cliaracter; the c/i/pcns is fixed, and forms a ])orlion of the head; the 

 u}»per lip is moveable, and is placed more forward. 

 , Labrum, or Labium, ini-erius, the piece which terminates the 

 mouth beneath, and which is sometimes l(~ngthened so as to form the 

 instrument called ligu/a. It is often bilid, and has tlie posterior pair 

 of feelers placed at the base. 



JVL'VNDibul.e, MancUhlcn: (P/. 10. Jig. 1. d.) two hard pieces, in sub- 

 stance resembling horn, which are placed one at each sideof the moulli, 

 below the upper lip. These have a lateral motion, while the upper 

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

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

 Ii.i\ing any of the palpi or feelers attached to them. In rapacious 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- 

 b;ige or leaves. 



iSLvxiLL.E {PL 10. fig. 1. c. — -fig. 2. a. the same magnified): two small 

 pieces generally of a somewluit membranaceous consistency, and in 

 figure different I'rom the mandibles. 'I'hese are connnonly indented at 

 the extremity, and nearly all ciliated at the inner edge. They 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 feelers, the pos- 

 terior ones take their origin from the sides of the maxillae, (fig. 2. I.e.) 

 Gale.e, Shields of the Mouth: two membranaceous appendages, 

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

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

 of the mouth conjointly with the lips. The gu/eo" are inserted at the 

 back of the jav/s, as is well exemplified in the Gryllus tribe. 



LiouLA. This is the part 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 texture, often bifid, and, if at- 



