Studies on Tipulidae. 159 



The clistinguishing characters of true Megistocerae are: their 

 crystalline wings, with a peculiar venation; the abseuce of a gibbo- 

 sity on the front, behind the antennae; the small male forceps; the 

 great length and slenderness of the legs etc. (Compare the details 

 below.) True Megistocerae occur only m the tropical regions of Asia 

 and Africa, and, as I am going to show, also of America. 



The extraordinary length of the antennae is not, in this case, 

 a generic character, first because it belongs (where it exists), to the 

 male sex only; and second because there are species in which both 

 the male and the female have short antennae. In the same way we 

 have Anisomerae, Eriocerae, Tipulae and Pachyrrhinae with long or 

 Short antennae in the male sex, within the same genus. 



Wiedemann, undoubtedly deceived by the smallness of the male 

 forceps of M. filipes and fuscana, took his own male types for fe- 

 male s. The fact is that the females of these two species were 

 hitherto unknown, and it was not stated anywhere, whether they had 

 long or Short antennae. During my visits to nearly all the european 

 museums I have met only with a Single female of M. fuscana in 

 the British Museum, collected by Mr. Wallace; its antennae are very 

 Short. When Macquart, D. E. Suppl. I, p. 18 corrected Wiedemann 

 about the sex of his specimens, this correction was based on a wrong 

 premise, on the antennae of Macquart's M. limhipennis , which, as 

 I have stated above, is not a Megistocera at all. 



Megistocerae with short antennae in both sexes have been found 

 in America only; a brazilian species, which I have seen in several 

 museums, and a species from Cuba, described by Macquart as a 

 Tipula; both must be referred to Megistocera, as, except the short- 

 ness of the male antennae, they agree in everything with that genus. 



I will give now a more detailed description of the characters of 

 Megistocera. 



The venation shows the following peculiarities : the brauch of 

 the second vein is nearly perpendicular and resembles a crossvein; 

 the auxiliary vein runs very close to the first vein and coalesces 

 with it near the stigma; there is a short vein, connecting this spot 

 with the Costa. The straight praefurca is nearly in a line with the 

 third vein; the continuation of the second vein forms a curve bet- 

 ween the tip of the praefurca and the stigma and then runs nearly 

 parallel to the third vein. The discal cell is very small; the inter- 

 calary vein is not emitted from it (in other words, the discal and 

 fifth posterior cells are not in contact). The seventh vein is short 

 and incurved into the anal angle, almost as in Trichocera. (Macquart's 

 figure in D. E. Suppl. I, Tab, 2, f. 4 gives an incorrect representation 



