196 



Dr. F. A. Dixey on 



in all the forms the general appearance of an elongated 

 lamina with rounded base and parallel sides. In specimens 

 of P. liliana from Mombasa, Taveta, the Dabida Hills, 

 Thiba River and near Machakos, the rounded base is 



Fig. G. — P. pigea, Boisd. Uncus X 54. 



Fig. 7. — P. gerda, Gr. Sm. and Kirb. Uncus X 54. 



greatly expanded and takes up by far the greater part of 

 the area of the lamina. The outline of the scale thus 

 becomes flask-shaped, the neck of the flask being repre- 

 sented by the portion of the lamina distal to the basal 

 expansion (fig. 8). The scent-scales of 

 a male specimen from Mombasa which 

 corresponds with the description and 

 figure of P. gerda by Grose Smith and 

 Kirby, exhibit precisely the same char- 

 acters as the foregoing. This appears 

 to favour the impression that the only 

 difference between gerda and liliana is 

 one of season. The specimens above 

 referred to (p. 193) from the Voi River 

 and Mlegwa closely resemble in aspect 

 the " gerda " from Mombasa ; their scent- 

 Fit i. 8. — P. liliana, scales, however, present a different 

 ] . x 310 nt appearance, the basal expansion being 

 p, granular patch, much reduced (fig. 9). So far as outline 

 goes, they are much like the corre- 

 sponding structures in P. simana, but they possess one 

 character in common with P. liliana which is not shared 

 by simana ; and which, in conjunction with another 

 feature presently to be mentioned, seems to indicate 



