6 7 



2. Note that they are irregularly oval, thicker 

 at one end than the other, and have a corrugated 

 surface in which are entangled numerous minute air 

 bubbles. 



3. Examine the surface of water left exposed 

 for several days in a tumbler, etc. Note, if Stegomyia 

 mosquitoes have ovi-posited, the presence of eggs 

 occurring singly or in parallel groups. Note that the 

 ova are larger than those of Anopbelines, and that they 

 hatch into Culicine-like larvae. 



4. The egg stage in S. calopus lasts twelve to 

 twenty-four hours. 



Fig. 22. Eggs of Stegomyia 



5. The eggs of Culicidae have but little resistance 

 to desiccation, but those of S. calopus will hatch after 

 being kept dry ' for three months. 



Taeniorbynchus. Examine natural waters, especi- 

 ally small pools with a dense growth of alga, swamp 

 pools, irrigated land, etc., for the egg-rafts. 



1. Observe the extreme length and narrowness 

 of the rafts. Note also how small a portion of the raft 

 is submerged. 



2. Observe that the ova are arranged as in Culex 

 rafts with the thicker end downwards, and that they 

 are smooth and have a micropilar apparatus. 



3. Endeavour to obtain the ova of known species 

 of Taeniorbyncbu^ by confining gravid females. Note 

 the shape of the rafts. 



