ON THE INSECTS FROM NEW BRITAIN. ' 393 



colour along the antero-external cross-vein. The only setae are, one behind each eye, and 

 a fringe of erect hairs along the free hind-margin of the vertex. The lialteres are white 

 and are placed at the junction of the perpendicular metanotum with the abdomen. 



Although the specimens above alluded to are certainly males, they differ considerably 

 in the form of the peculiar cephalic appendages. Each appendage consists of two parts: 

 a basal portion, which is a direct continuation of the membranous undersurface of the 

 head, prolonged immediately beneath the eye and causing a large emargination therefore ; 

 and a second terminal part, which is harder and separated from the basal part bj' a deep 

 constriction ; at this point the appendage appears to be capable of a great deal of move- 

 ment. In one of the two specimens the basal prominence is very large ; while in the 

 other (PI. XXXV. Fig. 12, 12 a, 12 &) it is quite small. 



Besides the two individuals described in the above lines, Dr Willey brought back 

 four other specimens considerably smaller in size, and concerning which I am in doubt as 

 to whether they may be a distinct species or small examples of G. willeyi. Two of them 

 are males, and two of them females. The smallest specimen is only 9 m.m. long. Both 

 the females and one of the males are entirely destitute of the peculiar cephalic append- 

 ages, while the other male possesses a vei-y small pair. I treat them as being a small 

 form of G. willeyi. 



