EXTERNAL ANATOMY OF INSECTS. 359 
of the lower margin of the Pharynz, observable in 
Eucera.* 
The seven organs of the mouth above defined, viz. the 
Labrum, Labium, the two Mandibule, the two Maxille, 
and the Lingua, constitute what may be denominated a 
perfect mouth, peculiar to those insects that masticate their 
food’. 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*. 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 are re- 
placed* by a jointed sheath, covered above at the 
base by the Labrum, without Labella (Liplets) at 
the end, and containing four long capillary lancets, 
and a short tongue’. It includes the Vagina, and 
Scalpella. 
* Vide Savigny Mém. sur les Anim. sans Vertebr. 1. i. 12—. 
> The majority of Hymenopterous insects, though they have the 
ordinary Trophi, are not masticators, using their mandibule only for 
purposes connected with their economy. 
© See his Mémoires sur les Animaux sans Vertebres, I. i. 
* T 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. 
© Prate VI. Fic. 7—9. 
