pamsde-s in Ned of Bombus derhaineUas. Ill 



having moved into an obli({iie position with the drying of 

 the balsam. This coinphjte symmetry is in contrast to 

 the condition existing in some: beetle-larvae (e. g. DascUlus : 

 see Carpenter and MacDowell, 5, p. 381, etc.). 



Labrum ami eptphartjnx (Fig. 3 a).— The labrum is clearly 

 separated from the head-capsnle, the sutuie being repre- 

 sented in fig. 3 A by a sinuate, dotted line. Dorsally the 

 labrum bears a rather long seta near either front angle : 

 these setae are not shown in tig. 3 A, which represents 

 only the ventral view. The front margin is neaily straight, 

 and set with 4 short spines ; between the median and 

 outer spine on either side is a clear, circular, area, re- 

 sembling a follicle from which the spine has been broken 

 away, but this does not seem to be the explanation, as 

 precisely the same arrangement has been observed in 

 three specimens. At the sides tlie labrum is raised into 

 lobes (cf. Helodes : see 5, pi. 35, fig. 10), which (in the 

 preparation from which fig. 3 a is drawn) project a little 

 in front of the general outline of the margin, and the large 

 lateral setae rise from behind (i. e. dorsal to) these lobes, 

 apparently in the fold betweeji the lobes and the general 

 margin.* The inner margins of these lobes are closely 

 set with hairs directed towards the middle line, and all 

 the median part of the labrum is covered with minute 

 prominences, some (or all) of which bear erect hairs : in 

 the middle are 4 much larger round follicles. A pig- 

 mented, thickened, chitinous band, rather like a misshapen 

 W, lies across the labrum, its median part bearing a trans- 

 verse series of 4 rounded teeth ; this is, presumably, part 

 of the epipharynx (cf . Helodes : see 5, pi. 35, fig. 10). No 

 attempt is made to interpret the pigmented, thickened, 

 chitinous parts (shaded in fig. 3 a) at the sides of the 

 labrum near its base ; nor the two curiously shaped pieces 

 (fig. 3 A, p.) meeting in the middle line, and the, greater 

 part of which lies against the head-capsule behind the 

 suture (fig. 3 a, su.) separating labrum from clypeus. 



Mandibles (Fig, 3 b). — ^The upper articulation of the 

 mandible is at a point on a level with the base of the 

 antemia, but nearer the middle line, and is effected by a 

 prominence of the head-capsule fitting into a hollow in 

 the upper edge of the base of the mandible : this articu- 



* Fig. 3 a shows 2 large setae om one side, 1 on the other. This 

 asyiiiinctiy is accidental, or due to individual variation. A second 

 Bj)ccimeii examined has 2 on either side. 



