1896.] ENTOMOLOGICAL NEV/S. I9I 



markable development of the secondary sexual characters, espe- 

 cially in the male. The peculiar modifications of the fore tarsi 

 in the males of many Dolichopodidae are well known, and Mr. 

 Snow has given a good account of the singular hind tarsi of 

 Platipeza calceata Snow and P. oncatipes Towns.,* but no Dip- 

 teron known to me has such peculiar middle tarsi as the Rham- 

 phomyia just described. In the case of the Dolichopodidae it is 

 certain from the observations of Dahlf and Aldrich;}: that the 

 ornamental tarsi are vibrated before the females during a kind of 

 courtship. It has been inferred that these ornaments very prob- 

 ably answer the same purpose as the remarkable plumes of many 

 male birds, e. g. the ocellate feathers of the peacock, Argus 

 pheasant, etc. As Rhamphomyia scaurissima probably flies in 

 swarms with a peculiar dancing movement like other species of 

 the genus, we may suppose that at such times the unusual tarsi 

 of the males would be dangled conspicuously and thus attract 

 the attention and stimulate the appetency of the inornate females. 

 In the female of Rh. scaurissima the great enlargement of the 

 discal cell must be regarded as a secondary sexual character, 



since the moderate dis- 

 cal cell of the male is 

 almost certainly of a 

 more generalized and 

 conservative nature. 

 Most species of Rham- 

 phomyia retain this 

 conservative type of 

 discal cell in both 

 sexes, but a certain 

 number of species 

 present the peculiar 

 enlargement in the fe- 

 male. It occurs in the 

 European Rh. spissi- 

 rostris Fall., Rh. ni- 

 gripes Fab. and Rh. 

 serpentata Loew, and 

 among the North American species in Loew's Rh. limbata, litu- 



* American Platipezidae, Kans. Univ. Quart, vol. iii, No. 2, 1894, pp. 143-152. 



t Die Insekten koennen Formen unterscheiden. Zool. Anzeiger 12 Jahrg. 1889, pp. 243-247. 



J Courtship among the Fiies, Am. Naturalist, vol. xxviii, 1894, pp. ,-5-37. 



Fig. 3. — Eight middle foot of Rh. scaurissima % 

 seen from the inside. 



