MUSCIDAE ACALYPTRATAE 



S05 



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 Lodo-e 

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

 1870 another swarm occurred in the same house if not in the 

 same room.^ 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 be 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 Borhorus. The 

 Diopsidae — none of which are European 

 — have the sides of the head produced 

 into long horns, at the extremity of which 

 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 Elaphomyia, 

 parts of the head are prolonged into 

 horns of very diverse forms according to pia. lii.-Odyphus (Para- 

 the species, but bearing on the whole a 

 great resemblance to miniature stag- 

 horns. A genus {Giraffomyici) 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 

 Cdijf'h.us ; they do not look like flies at all, owing to the scutellum 

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



■• Loudon's Magazine, v. 1832, p. 302 ; P. ent. Soc. London, 1871, p. .^. 



celyjAus) sp. West Africa. 

 A, The fiy seen from 

 above ; a, scutellum ; h, 

 base of "wing : B, profile, 

 with tip of abdomen bent 

 downwards ; a, scutellum ; 

 b, h, wing ; c, part of 

 abdomen. 



