67 
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 Anophelines , 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 4 dry 5 for three months. 
T aeniorhynchus. —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 Taeniorhynchus , by confining gravid females. Note 
the shape of the rafts. 
