INSECTS : TIIEIK MOUTHS. 



173 



like tip of the labium expands into two concave leaves, 

 like the bracts of a bud, and displays two pairs of more 

 delicate leaves within thcni. Then from a c;roove alonor 

 the upper side of the lahhnn, spring out several lila- 

 nients of ffreat elasticitv and of the most delicate tenu- 

 itv. One pair of these represent the mandibles ; they 

 consist each of a verv narrow blade with a stronger 

 back like that of a scythe. Tlieir tip is brought to a 

 most acute point, and the edge in immediate proximity 

 to this is cut into about nine teeth pointing backward : 

 the rest of the edge is smootli, 

 but the whole blade is crossed 

 by a multitude of oblique lines 

 c;f great delicacy, Avhicli may bo 

 intended to keep the edge con- 

 stantly keen. 



JS^ext come the inaxUlcs^ or 

 lower jaws, horny filaments as 

 long as the former, but still more 

 delicate, constituting simple cut- 

 ting lancets, with a back and a 

 keen blade, a little M-idening at 

 the tip. 



Besides these there is the 

 tongue^ consisting of a central 

 rod which is distinctly tubular, 

 and of a thin blade on each side,, 

 fine-edged and drawn to an acute 

 point. And also the lalirum or 

 upper lip, an organ having the 

 s:ime general form, but consti- 

 tuting an imperfect tube ; a tube, 

 that is to say, from M-hich about a third of the periphery 



LANCETS OP FEMALE GKAT. 



(t. liibium. (I. io)igue. 



h, h. '•nimiiihles. e. lab rum. 

 c, c. maxillcB. 



