Chap. X. DIPTERA AND HEMTPTERA. 349 



is in the genus Bibio, in which the males are blackish 

 or quite black, and the females obscure brownish-orange. 

 The genus Elaphomvia, discovered by Mr. Wallace 18 in 

 New Guinea, is highly remarkable, as the males are 

 furnished with horns, of which the females are quite 

 destitute. The horns spring from beneath the eyes, and 

 curiously resemble those of stags, being either branched 

 or palmated. They equal in length the whole of the 

 body in one of the species. They might be thought 

 to serve for fighting, but as in one species they are 

 of a beautiful pink colour, edged with black, with a 

 pale central stripe, and as these insects have altogether 

 a very elegant appearance, it is perhaps more pro- 

 bable that the horns serve as ornaments. That the 

 males of some Diptera fight together is certain ; for 

 Prof. Westwoed 19 has several times seen this with some 

 species of Tipula or Harry-long-legs. Many observers 

 believe that when gnats (Culickke) dance in the air in 

 a body, alternately rising and falling, the males are 

 courting the females. The mental faculties of the 

 Diptera are probably fairly well developed, for their 

 nervous system is more highly developed than in most 

 other Orders of insects. 20 



Order, He?niptera (Field-Bugs). — Mr. J. W. Douglas, 

 who has particularly attended to the British species, has 

 kindly aiven me an account of their sexual differences. 

 The males of some species are furnished with wings, 

 whilst the females are windless ; the sexes differ in the 

 form of the body and elytra ; in the second joints of 

 their antennae and in their tarsi ; but as the signification 



18 « The Malay Archipelago,' vol. ii. 1809, p. 313. 



19 ' Modern Classification of Insects,' vol. ii. 1840, p. 526. 



30 See Mr. B. T. Lowne's very interesting work, ' On the Anatomy of 

 the Blow-Fly, Mnsca vomitoria,' 1870, p. 14. 



