MORPHOLOGICAL CHAXGES OF STEGOMYIA FASCIATA. 307 



In addition, there are a few characters which are pecuhar to the earhest phases. 

 There is for example the double sub-plumose hair, representing the plume on the 

 antenna in the first phase only ; the 4 to 6 elements in the comb, which changes to 

 8 to 10 in the second phase and may thereafter remain unchanged until the end of the 

 larval period ; and the simple formula for the hairs on the dorsal edge of the anal 

 segment, only found in the first and second phases. It is possible that some of these 

 perhaps indicate some earlier stage in the evolution of the species. For if in the 

 development of the individual the evolutionary history of the species is recapitulated, 

 one might expect to find in the larval phases of Stegomijia fasciata some indications 

 as to the other species and genera of mosquito most nearly related to it. To do this 

 it would be necessary to study the changes found in successive larval phases in other 

 mosquitos and to compare them with those observed in this species. This cannot be 

 done at present, as, so far as I am aware, the changes that take place during the larval 

 period have not been completely recorded in the case of any other African species. 

 A comparative study of this sort might, however, be of great assistance in formulating 

 a n;itnv;il svstoni of classification. 



