— 72 — 



Labrum. — The labrum is small and oblong in shape with 

 its latero-cephalic corners rounded. The breadth (dextro- 

 sinstral) is about three times its length (caudo-cephalic). 



Mandibles. — Partially concealed beneath the labrum are 

 the spoon-shaped mandibles. With forceps or needle, press 

 the mandibles apart at their tips (press laterad). Note that 

 the mandibles are not toothed, but are rather paddle- or spoon- 

 like at the tips. Remove and make a drawing of a mandible. 



Remove both mandibles and labrum, and grasp the re- 

 maining protruding parts with forceps and carefully pull 

 them loose from the head. Wash while still held in the 

 forceps, and mount in glycerine on a glass slide. Before 

 reading further the student should endeavor to name the 

 various parts presented before him on the slide. He should 

 refresh his memory as to the relations of the various sclerites 

 of the labium and maxillae, by reference to his drawings of 

 these parts in the insects already studied. 



Make a drawing of the maxillae and labium, and name the 

 parts, tentatively. Compare the result with the notes fol- 

 lowing : — 



Maxillae. — The parts of each maxilla present are the car- 

 do, stipes, galea (or lacina ; one of the two is probably 

 wanting), maxillary palpi, and possibly the palpifer. 



Cardo. — The cardo, or proximal part of the maxilla is a- 

 rather long, slender, strongly-chitiuized sclerite, somewhat 

 resembling a human femur or thigh-bone in shape. At its 

 proximal end it terminates in two unequal prongs, the point 

 of the larger being bluntly rounded. At its distal end 

 (articulating with the stipes) it expands club-like. 



Stipes. — The stipes is an irregular, elongate sclerite, strongly 

 chitinized. Its proximal end is bluntly rounded and swollen. 

 The stipes articulates with the proximal segment^of the galea 

 (see below) by a long diagonal face. 



Galea. — The galea (we incline to believe this part homolo- 



