4 CRUSTACEA, ARACHNIDES ? IXSECTA. 



cover them before and behind are named labia(l), and the 

 front one, in particular, lafoum. The palpi are articulated 

 filaments attached to the jaws or to the lower lip, and appear 

 to be employed by the animal in recognizing its food. The 

 form of these various organs determines the nature of the re- 

 gimen with as much precision as the teeth of quadrupeds. The 

 ligula, or tongue, commonly adheres to the lower lip(2). 

 Sometimes, in the Apes and other Hymenopterous insects, 

 it is considerably elongated, as are also the jaws, forming a 

 sort of false proboscis (promuscis) at the base of which is the 

 pharynx, and frequently covered by a sort of sub-labrum, 

 styled by M. Savigny the epipharynx{3). At other times, 



(1) We here more particularly allude to Insects with six feet, or to the Hexa- 

 poda. 



(2) Or rather labium, since the other is termed labnim. It is protected, before, 

 by a horny production formed by a cutaneous prolongation, and articulated at the 

 base with an inferior portion of the head called the mentum or chin. Its palpi, 

 always two in number, are distinguished'from those of the maxillae by the epithet 

 labial. When the latter amount to four they are designated as external and inter- 

 nal; they are considered as a modification of the external and terminal division of 

 the maxillae. This production, which, in his Ulonates or the Orthoptera, Fabricius 

 termed the Galea, is still the same maxillary division, but more dilated, arched, and 

 fitted to cover the internal division which, here, on account of its scaly consistence 

 and of its teeth, resembles a mandible. In the last insects, and particularly in the 

 Libellula:, the interior of the buccal cavity presents a soft or vesicular body, dis- 

 tinct from the lip, and which, compared to the Crustacea, appears to be the true 

 tongue labium, Fab. This part is perhaps represented by those lateral divi- 

 sions of the ligula termed paraglossse. (See the Coleoptera Carnivora, Hydro- 

 phili, Staphylini, the two pencil-shaped pieces that terminate the lip of the Lucani, 

 Apiarise, &c) The above mentioned Insects, the Orthoptera and the Libellulas of 

 Linnaeus, evidently demonstrate that this membranous and terminal portion of the 

 inferior lip, which projects more or less between its palpi, and is particularly elon- 

 gated in several of the Hymenoptera, is very distinct from that internal caruncle 

 which I consider the tongue properly so called; notwithstanding this, nearly all 

 Entomologists designate this external extremity of the lip by the name of ligula, 

 or languette. To say, however, that the tongue properly so called, is usually so 

 intimately connected with the lip that at the first glance they seem to be con- 

 founded, is correct. The pharynx is situated in the middle of the anterior face of 

 this lip a little above its root, and in the Coleoptera provided with paraglossae, at 

 their point of union. In order to understand well the primitive composition of 

 the under lip, it must be studied in the larvae, and chiefly in those of the Aquatic 

 Carnivorous Coleoptera. See General Observations on Insects. 



(3) There is a membranous production beneath the labrum, in many Coleop- 



