NOTES ON ANOPHELES IN CEYLON. 



277 



Possibly the poison is conveyed by the other species of Anopheles. I 

 have found here another species which at the present moment is 



very rare, at least so far I have only taken two specimens. 



[I have been unable to determine this species to my satisfaction. It is very near 

 A. rossii, but has a more silvery thorax. Cf A. rossii, also, Capt. James writes: 

 *' Experimentally we have proved that the three species of the human malaria 

 parasites will develop in this mosquito, but we have never yet found it infected in 

 nature. 1 *— E. E. G.] 



It is possible that for some obscure reason it is now approaching 

 extinction ; possibly it will become active at the onset of the South- 

 West Monsoon. It may puzzle some of my readers that this should be a 

 dry wind, but the explanation is that it loses its moisture when passing 

 over the hill country in the south-west of the Island. 



Note. — June 20th. So far there has been an almost entire absence 

 of fever this year, Anojiheles still breeding in the tanks. 



[Recent study of the lame of mosquitoes of the genus Anopheles has shown that 

 good specific characters may be found in the form of the 4 frontal hairs always 

 present on the anterior margin of the head. They are usually more or less obscured 

 by the extended whorl organs, and can be best observed when those organs are 

 retracted or removed. In some species, the 4 hairs are simple and unbranched : 

 in others, the inner hairs may be simple and the outer pair branched : in yet others 

 both pairs may be plumose, in varying degrees. 



In the present species, the median hairs are slightly, and the outer hairs densely 

 plumose (see fig. below) :— 



Frontal hairs of larva of Anopheles fulig inosus. 



In Vol. Ill of his " Monograph of the Culicidse," Mr. Theobald has sub-divided 

 the genus Anopheles, and now places, fuliginosus in the genus NyssorhyncJms of. 

 Blauchard.— E.E.G.] 



