WITH ARTICULATED FEET. 133 



especially named mandibles ; the pieces which cover them 

 in front and rear, are named lips ; and that of the front in 

 particular receives the name o( labrum. This remark belongs 

 more especially to the hexapod insects. Certain articulated 

 filaments attached to the jaws, or the under lip, and which 

 appear to serve the animal for the purpose of recognizing its 

 food, are termed palpi, or antetinulac. The forms of these 

 various organs determine the nature of the aliment as pre- 

 cisely as do the teeth of quadrupeds. To the lower lip the 

 tongue, or ligula, commonly adheres. Sometimes (the hees 

 and many other hymenopterous insects,) it is considerably 

 prolonged, as well as the jaws, and forms a sort of false pro- 

 boscis (promuscis) having the pharynx at its base, often 

 covered by a species of sub-labrum, called by M. Savigny 

 epipharynx. Sometimes (lieiniptera and diptera^ the man- 

 dibles and jaws are replaced by scaly pieces, in the form of 

 bristles or lancets, received in a tubular elongated sheath, 

 either cylindrical and articulated, or more or less elbowed, 

 and terminated by sorts of lips. These parts then compose a 

 true proboscis. In other sucking insects (lepidopteraj the 

 jaws alone are considerably prolonged, and unite to form a 

 tubular body, in the form of a thread, having the appearance 

 of a long tongue, very fine, and rolled up spirally, fspiri- 

 trompe, Lat.) ; the other parts of the mouth are very much 

 diminished. Sometimes, as in many Crustacea, the anterior 

 feet approach the jaws, assuming their form, exercising a 

 part of their functions, and one might then say that the jaws 

 are multiplied. It may even happen that the jaws shall be so 

 much reduced, that the maxillary feet, otherwise jaw-feet, 

 may replace them altogether. But whatever may be the mo- 

 difications of these parts, there is always a means of recog- 

 nizing them, and of reducing these changes to a general 

 type. 



