THE EARLY STAGES OF WEST AFRICAN MOSQUITOS. 



107 



Fig. 1. Diagram showing the arrangement of the setae on 

 the cephalothorax of the pupa of Culex decens or G. invidiosus. 



Table II. 

 A Comparison of the Ceplmlo-thoracic Setae of the Pupae ofC decens and C. invidiosus. 



Seta. 



0. decens. 



C. invidiosus. 



Post-ocular, 











Superior ; rather long, not 











especially strong 



3 





3-4, 



usually 3 



Median ; rather long, not 











especially strong 



4-6, 



usually 4 



4-5, 



usually 4 



Inferior ; rather long, not 











especially strong 



3-4 





3 





Antero -thoracic, 











Lower anterior ; moderate 











length, constituent hairs 











rather delicate . . 



4-5 





4-7 





Upper anterior ; rather 











small and delicate 



1-5 





3 





Lower posterior ; long, but 











not very strong . . 



2 





2-3, 



usually 2 



Upper posterior ; rather 











small and delicate, 











situated above the 











lower posterior seta . . 



1-4 





2-5 





Dorsal ; moderate length and 











strength . . 



2-4, 



usually 4 



3-5 





Supra-alar ; moderate length and 











strength . . 



2 





2-3, 



usually 2 



Postero-thoracic, 











Internal ; well- developed 











tuft of moderate length 











and strength 



5-8 





5-8 





Median ; rather long and 











strong 



2-3, 



usually 2 



2 





External ; tuft of moderate 











length and strength, or 











rather long 



3-5 





3-5 





