INSECTS : THEIE MOUTHS. 



1Y3 



like tip of the lahiinn expands into two concave loaves, 

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

 delicate leaves within them. Then from a groove along 

 the upper side of the lahiiim, spring out several fila- 

 ments of great elasticity and of the most delicate tenu- 

 ity. One pair of these represent the mandibles ; they 

 consist each of a very narrow blade with a stronger 

 back like that of a scythe. Their 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 smooth, 

 but the whole blade is crossed 

 by a multitude of oblique lines 

 of great delicacy, which may be 

 intended to keep the edge con- 

 stantly keen. 



Next come the maxillce, 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 widening 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 lairum or 

 upper lip, an organ having the 

 same general form, but consti- 

 tuting an imperfect tube ; a tube, 

 that is to say, from which about a third of the periphery 



LANCETS OF FEMALE GNAT. 



a. labium. d. tongue. 



&, h. Tnandihlea. e. labrum. 

 c, c. 'nia^illoi. 



