•252 GNATS OR MOSQUITOES — CHAPTER IX 



Anyone who is at the pains to compare closely the above 

 faunistic lists will find no difficulty in discovering numerous 

 other instances of wide as well as of scattered distribution, 

 but as regards the latter character, it must be remembered 

 that wide gaps between the recorded haunts of certain 

 species may be often merely due to our lack of information 

 as to the fauna of the intervening countries, which will 

 be filled up as our knowledge increases. It must not be 

 forgotten, too, that the closest morphological resemblance 

 does not necessarily imply specific identity, and that some 

 of the eccentric distributions that may be noticed may be 

 referable to a close external resemblance of really distinct 

 species ; in illustration of which, it may be instanced that 

 cases have been met with by both Mr. Theobald and 

 myself in which specimens have been sent by well-known 

 naturalists as of one species, and which were certainly 

 well-nigh identical, marking for marking, were yet found, 

 on close examination of the form of their scales, to belong 

 to quite different genera. 



It will be also seen that, speaking generally, the species 

 of Anopheles have seldom so wide a distribution as that of 

 many Culices, while the Stegomyia are the most widely 

 distributed of all, S. fasciata (Fabr.) actually belting the 

 world, but not, it will be noticed, extending northward of 

 about lat. 40°, or south of the corresponding isotherm. In 

 the north C. pipiens is possibly as widely spread, though 

 there is at present a wide gap in Asia, from whence we 

 have little or no information. I doubt, however, if this 

 species extends much south of Italy, as although typical 

 specimens have been obtained from the northern part of 

 that country, I suspect that its place is taken in the south 

 by C. fatigans, Wied., which certainly also occurs there. 

 I am aware that Professor Grassi regards these two species 

 as identical, but believe that he has been led to that con- 

 clusion by having to deal with C. fatigans, as to judge by 

 the figure in his recent work (" G. S. Z.," Tav. iv., fig. 30) 

 it is really that species, and not C. pipiens, to which he 

 refers, as the drawmg clearly shows the comparatively short 

 male palpi, which afford one of the readiest means of dis- 



