S60 EXTERNAL ANATOMY OF INSECTS. 



of the lower margin of the Pharynx, observable in 

 Eucera F. a 



The seven organs of the mouth above defined, viz. the 

 Labrum, Labium, the two Mandibular, the two Maxillae, 

 and the Lingua, constitute what may be denominated a 

 perfect mouth, peculiar to those insects that masticate their 

 food b . In those that take it by suction, the Trophi, to 

 adapt them for that purpose, assume a variety of forms, 

 and should be distinguished by as many appellations. In 

 almost every case, however, the rudiments or representa- 

 tives of the above organs have been detected by the elabo- 

 rate researches of that learned, and able zoologist, M. Sa- 

 vigny c . I shall next subjoin definitions of the principal 

 kinds of suctorious mouths. 



2. Promuscis (the Promuscis). The oral instrument of 

 Hemiptera, in which the ordinary Trophi axe re- 

 placed d by a jointed sheath, covered above at the 

 base by the Labrum, without Lobelia (Liplets) at 

 the end, and containing four long capillary lancets, 

 and a short tongue e . It includes the Vagina, and 

 Scalptella. 



a Vide Savigny Mem. sur les Anim. sans Vertebr. I. i. 12 — . 



b The majority of Hymenopterous insects, though they have the 

 ordinary Tropin, are not masticators, using their mandibula only for 

 purposes connected with their economy. 



c See his Memoires sur les Animaux sans Vertebres, I. i. 



d I have used this word here and on a former occasion (see above, 

 p. 29), perhaps not with strict propriety, in the sense of the French 

 word remplacer, for which we seem to have no single corresponding 

 word in our language. 



e Plate VI. Fig. 7—9. 



