Anopheles rossi. 



Characters distinguishing this mosquito from other species. 

 From A. stephensi it is distinguished by the absence of scales on the 

 abdomen, by the markings on the palpi, and by the absence of 

 speckling of the legs. 



This mosquito might be confounded with those of Group II, 

 especially with punctulatus, but an examination of the palpi would 

 prevent any error, for the members of that group have four bands 

 on the palpi. 



This mosquito very closely resembles costalis but differs 

 from it chiefly in the fact that costalis has a white interruption in 

 the black area on the first longitudinal vein, opposite the penulti- 

 mate black costal spot, and has three black spots on the sixth longi- 

 tudinal vein in place of two. These, however, are merely colour 

 variations and can hardly be considered of specific value. 



We can confirm Colonel Giles' statement that there is a tuft of 

 white scales on the front of the thorax as well as a small patch of 

 spindle-shaped scales on the last abdominal segment. Mr. Theobald 

 apparently considers that these scales are absent, and for that reason 

 has placed the species in the genus Myzomyia. A classification based 

 upon characters about which it is possible for so much difference of 

 opinion to exist, cannot, we think, be considered a very useful one. 



We may here refer to a specimen which Mr. Theobald has 

 placed as the type of a new genus Aldrichia. This genus is based 

 on a single specimen, which was found among the types of A. rossi 

 deposited in the British Museum. It differs from all other " ano- 

 pheles " in the fact that the entire dorsum of the abdomen is cover- 

 ed with flat imbricated scales arranged exactly as in mosquitoes of 

 the genus Culex. In other respects the specimen, which has been 

 named Aldrichia error, appears to resemble rossi very closely, 

 and Colonel Giles is of opinion that in all probability it represents 

 merely an abnormality. He states that when examining a number 

 of specimens of culicifacies he came across one the abdomen of 

 which was similarly scaled (see his description cf this species, Hand- 

 book, 2nd Ed., p. 317, and his Revision of the Anophelinas, pp. 

 9 and 29), so that observers should certainly be on the look out for 

 specimens presenting this curious character, in order that the 

 question as to whether such specimens are abnormalities or not 

 may be cleared up. 



U2] 



