304 



J. W. SrOTT MACFIE. 



somewhat at botli ends, and although the distal ends are rounded, they can hardly 

 be said to be " strikingly blunt " during life or in recently preserved specimens. 

 The ratio of length to breadtli is usually 5 to 1. 



In the last phase a number of highly refractile discs become conspicuous in the 

 papillae. These are the nuclei of the delicate tissue of which these organs are com- 

 posed, and they can readily be brought out by staining with haematoxylin. The 

 presence of these nuclei is not of course peculiar to this phase, but they are 

 more obvious and more likely to attract attention in unstained specimens at this time 

 tlian in the earlier phases. 



Fig. 7. Larva of Stegomyia fasciata ; posterior end in the fourth stage. 



Dorsal Hairs on the Anal Segment (figs. 6, 7). On the dorsal edge of the anal 

 segment there are four long hairs which were described by Wesche (1910)* as simple, 

 and by Boyce (1911)")" as bifurcated. As a matter of fact the character of these 

 hairs varies with the age of the larva. In the first and second phases in every 

 lai-va examined they were simple ; in the third phase the two more dorsal hairs 

 were bifurcated, but the two ventral ones remained simple ; in the fourth or last 

 phase the hairs had undergone greater subdivision, the dorsal pair being divided into 

 from 3 to 5 parts each, and the ventral pair being usually bifurcated, but sometimes 

 remaining simple. In this last phase the number of hairs was very variable, some- 



* Wesche, W. Bull. Ent. Res., Vol. I, p. 25. 

 t Boyce, Sir R. Bull. Ent. Ros., Vol. I, p. 244. 



