53 [ 473 ] 



Sefiform, or setaceous; bristle-UJce; long and slender, but tapering 

 towards the tip. 



Moniliform, or bead-lil-c; when the joints are of about the same size, and 

 round, so as to resemble a string of beads. 



Serrate^ or saic-toothed; when each joint is somewhat triangular, and a 

 little i^rominent and pointed on the inner side. 



Pectinate^ or comh-toothed; when the inner angles of the joints are con- 

 siderably prolonged. 



Bi-2)ectinafe, or double comb-toothed; jiectinate on both sides. 



Clavate, or club-shaped; gradually enlarging towards the tip. 



Capitate, or Tcnobbed; when a few of the terminal joints are abruptly en- 

 larged. 



Lamellate; when the joints which compose the knob are prolonged on 

 their inner side, in the form of plates. 



The Eyes. — We have briefly discribed the mechanism of the eyes when 

 treating of the sense of sight. They are uniformly of a round or oval 

 sliape, and sometimes notched on their inner side, to give place for the 

 insertion of the antenuie. In a few instances they are placed at the end 

 of foot-stalks made by a lateral prolongation of the head. 



The Tro])Jii, or parts of the mouth. — The mouths of insects present 

 two strongly marked variations, one of which is fitted for guamng solid 

 substances, and is aiUed the mandibulate, or gnawing mouth ; and the 

 other is fitted for sucking fluid nutriment, and is called the haustellate, 

 or suctorial ihouth. 



The mandibulate mouth is composed of six pieces, more or less dis- 

 tinct, and their appendages. First, the labrum, or upper lip : a horny, 

 usually somewhat semi-circular plate, attached to the anterior and in- 

 ferior edge of the.head, and serving to close and protect the mouth in front. 



Then, the Mmidibles, or upper jaws; a j)air of very hard, horny 

 pieces, more or less hooked at the point, and often toothed on their in- 

 ner sides, which work together laterally, somewhat like the blades of a 

 pair of scissors. These are the true biting, gnawing, or masticating 

 organs. 



iSText are the Maxillae, or lower jaws; a pair of organs, working lat- 

 erally like the mandibles, but softer and more pUable in their texture, 

 generally divided into two lobes at their extremity, which are furnished 

 more or less with hairs. The maxillae undoubtedly assist in the opera- 

 tion of eating, but the precise part which they perform is not well un- 

 derstood. 



Behind the maxillae is a single piece which partially closes the mouth 

 beliind, and which may therefore be considered as the counter-j^art of 

 the labrum or upper lip, and is accordingly called the labium or lower lip. 



In the Coleoptera this piece is usually attached at its base to the an 

 terior face of an elevated ridge upon the under side of the head, which 



