262 



H. TETLEY, 



proboscis into the flower, the insect would naturally make the two labella diverge 

 so as to suck up the nectar ; this would have the effect of making the spines project 

 into the sides of the flower and would give the insect a slightly firmer hold while 

 it was hovering. Such an arrangement would, I think, be a help, considering the 

 great length of the proboscis. 



III. Mouth-parts of the Male. 



(1). Mandibles. — Absent. 



(2). Maxilla (text-fig. 8). — Differs very strikingly from the maxilla of the female 

 in the method of its connection with the head. In the female, as stated above, the 

 base of the maxilla is inserted well inside the head. In the male there is no 

 articulation, but the whole organ, with its palp, lies in a membranous area situated 

 within a hollow. The latter is formed firstly by the forward prolongation of the 

 central anterior region of the submentum, and secondly by the hollowing out of the 



Fig. 8. Basal portion of right 

 maxilla of $ (X 44) : g, galea ; 

 I, rudiment of lacinia ; p, maxil- 

 lary palp ; st, stipes. 



parts of the genae lying on either side of this process of the submentum. Thus it 

 will be seen that the maxilla in the male is not nearly so firmly welded to the head 

 as it is in the female. The maxilla consists of stipes, lacinia, galea and palp. 



Car do. — Absent. 



Stipes. — A broad, very deeply chitinised rod, and slightly curved. It has a distinct 

 articulation with the galea, and is not continuous with it as in the female. The 

 articulation is straight, but faces obliquely towards the middle line. 



Lacinia. — A small projection from the inner basal corner of the galea, slightly 

 hooked at its extremity, and pointing towards the head. Its inner edge is stronger 

 than the outer one, as it has a ridge running down it. A straight line, running 

 parallel to the edge of the galea, can be seen separating it off from the latter piece. 



Galea. — Approximately of the same length as in the female. It is slightly curved 

 outwards at the base, but the remainder is straight until close to the apex, where it 

 narrows. The inner edge commences to narrow before the outer one. The galea 

 is more deeply chitinised at the base than elsewhere, the chitin decreasing over the 



