240 PERCY SLADEN TRUST EXPEDITION 
truncate on the inner side in the basal portion; joint 2 longer than 1, slightly incrassate, 
convex on the inner side and nearly straight on the outer side, constricted at the 
base, which causes the swollen articulating portion sometimes to appear as a small 
separate joint ; the antenna is slightly elbowed at the base of joint 3, jomts 3—6 
being directed shghtly outwards; jomts 3—5 subequal in length, subcylindric, broader 
at apex than base, gradually broadening towards the apex of the antenna; joint 6 
longest, in g nearly as long as 83—5 together, in $ about as long as 4 and 5 together, 
gradually broadening towards the bluntly-rounded apex. The apical portion of this 
6th joimt bears beneath a very remarkable excavation, with clean-cut and slightly 
overhanging edge; this excavation is larger in f than in ? and differently shaped 

Fig. 3. Rhabdotohispa scotti, 9, x 8. Fig. 4. Rhabdotohispa scotti, Vig. 5. Rhabdotohispa scottr; last joint 
right antenna of 2 from of right antenna of @ and ¢, viewed 
above. from beneath, showing the outline of 
the sensory pit (the two figures to 
same scale). 
(Fig. 5), but in both sexes it is roughly U-shaped, the limb on the inner side of the 
antenna being much broader than that on the outer side. It has not been possible 
to examine satisfactorily the minute structure of the surface of the excavation, but 
a balsam preparation under a high power shows the presence of small groups of 
papilliform structures situated in pits which are surrounded by a dense mass of a 
special form of short sete. Mouth-parts in a slight hollow situated transversely 
between the eyes, the lower margin of which it reaches on either side, surrounded 
by a slightly raised margin which is interrupted behind, and at either side in front. 
Labrum pale and membranous, bearing on its front (upper) surface setee placed in a 
sinuate transverse line some way behind the front margin. Mandibles subtriangular. 
