DOLIC110PEZA. 353 



Section DOLICHOPEZINI. 



As previously stated, the excessively delicate and long legs afford 

 the principal character by which members of this section may be' 

 known. They have a habit of dancing up and down in the air in 

 small swarms after the nature of EPHEMEBIDJE, a habit equally 

 affected by various genera of TIPULID.S; Dicranomyia, Trichocera, 

 and in fact many others.* 



Apart from the length of leg common to all, the genera in this 

 section are mainly contradictory, so to speak. Taking the four 

 Oriental genera, Dolichopeza and Scamboneura possess thirteen- 

 jointed antennae, Megistocera and Tanypremna less than thirteen. 

 The two former genera have complex genitalia in the male, the 

 two latter more simple ones. Dolichopeza has no nasus, but this 

 is distinct in /Scamboneura and Megistocera. Tanypremna has no 

 neck, yet Scamboneura and others have short ones. The anterior 

 branch of the 2nd longitudinal vein is present in Megistocera aad 

 Tanypremna, absent in the, other two ; the anterior branch of 

 the 4th vein is twice forked in Dolichopeza, only once forked in 

 the other three genera ; the discal cell is present in Meyistocera 

 and Tanypremna, absent in Dolicliopeza and Scamboneura. In 

 Megistocera the 5th posterior cell is not in contact with the discal 

 cell, as it is in Tanypremna. 



The following is the only genus which occurs within our 

 limits : 



Genus DOLICHOPEZA, Curt. 



Dolichopeza, Curtis, Brit. Entom. p. 62 (1825). 

 Apeilesis, Macquart, Dipt. Exot. Supp. i, p. 8 (1840). 

 Leptina, Meigen, Syst. Besch. vi, pi. Ixv, fig. 10 (18-30). 



GENOTYPE. D. sylvicola, Curt. ; by original designation. 



Head transverse ; frons arched ; eyes rounded. Proboscis 

 rather prominent but short, the uppersicle hairy ; no nasus ; the 

 palpi four-jointed, long, cylindrical, whip-like. Antennae thirteen- 

 jointed, the ultimate one very small ; t structure of scape and 

 flagellum normal. Thorax as in Tipula^ only rather more delicate. 

 Abdomen much as in Tipula but more slender. The genitalia 

 slightly swollen, bearing some resemblance to those of Pachyrhina. $ 



* It is curious that most insects with exceedingly long and delicate legs, 

 wings, antennae, or caudal seta; possess this habit of aerial dancing, the length 

 of limbs presumably acting as a means of balance. 



t The antenna} were originally described as possessing twelve joints only ; 

 Zetterstedt, Meigen, Curtis, and Walker uniting in this error. Sohiner sug- 

 gested that thirteen were present, this number being subsequently confirmed 

 by Oaten Sacken's examination of living specimens of both sexes. 



} Osten Sacken observed the union of the sexes in a European species, pro- 

 bably D. sylvicola, Mg. "The female was hanging down from some support 

 to which it held on by its front legs ; it bore the whole weight of the male, who 

 was fastened to it merely by the forceps, hanging head downwards,. with his 

 legs stretched out. I have seen Bittacomorpha copulate in the same manner." 



