VII 



MUSCIDAE ACALYPTRATAE 



505 



famous for the curious habit of entering human habitations in 

 great swarms : frequently many millions being found in a single 

 apartment. Instances of this habit have been recorded both in 

 France and England, Cambridge being perhaps the place where the 

 phenomenon is most persistently exhibited. In the year 1831 an 

 enormous swarm of C. lineata was found in the Provost's Lodge 

 at King's College and was recorded by Leonard Jenyns ; in 

 18*70 another swarm occurred in the same house if not in the 

 same room. 1 Of late years such swarms have occurred in certain 

 apartments in the Museums (which are not far from King's 

 College), and always in the same apartments. No clue whatever 

 can be obtained as to their origin ; and the manner in which 

 these flies are guided to a small area in 

 numbers that must be seen to lie be- 

 lieved, is most mysterious. These swarms 

 always occur in the autumn, and it has 

 been suggested that the individuals are 

 seeking winter quarters. 



Several members of the Acalyptratae 

 have small wings or are wingless, as in 

 some of our species of Horborus. The 

 Diopsidae none of which are European 

 have the sides of the head produced 

 into long horns, at the extremity of which f, 

 are placed the eyes and antennae ; these '. 

 curiosities (Fig. 240) are apparently com- 

 mon in both Hindostan and Africa. In 

 the horned flies of the genus Elapliomyia, 

 parts of the head are prolonged into 

 horns of very diverse forms according to 

 the species, but bearin 

 great resemblance to miniature 

 horns. A genus (Giraffomyia) with a long 

 neck, and with partially segmented appen- 

 dages, instead of horns on the head, has 

 been recently discovered by Dr. Arthur 

 Willey in New Britain. Equally remarkable are the species of 

 ( 'fly pirns ; they do not look like flies at all, owing to the scutellum 

 being inflated and enlarged so as to cover all the posterior parts 



1 London 's Mwj~iiu:. v. 1832, p. 302 ; P. cut. Soc. London, 1871, p. x. 



ig on the whole a 



stag- 



FIG. 241. ( 



celyphus) sp. West Africa. 

 A, The fly seen from 

 above ; a, scutellum ; b, 

 base of wing : B, proliK 

 with tip of abdomen bent 

 downwards ; a, scutellum ; 

 b, 6, wing ; c, part ot 

 abdomen. 



