466 PROCEEDINGS OF THE ACADEMY OF [Sept., 
variation in the number of antennal segments is found in other 
genera of crane-flies {Ciedonia, 15 to 24 segments; Cerozodia, 32 to 
39 segments; Tanyderus, 17 to 25 segments), and consequently too 
much significance should not be placed upon this variable character 
in these groups. 
The genus Padujrrhina was described at a much later date, and 
consequently the numerous species known throughout the world 
under this name must be referred to Nephrotoma. The change in 
the American species affects all of the described forms with the excep- 
tion of collaris Say, polymera Loew, nobilis Loew, unimaculata Loew, 
calif ornica Doane, trinidadensis Alexander and macrosterna Alexander, 
which should be referred to the genus Tipida as discussed below. 
The discovery of an ultimate character to separate the species of 
Nephrotoma from those of Tipula is still largely a desideratum. 
There are a number of characters which, if used in combination, 
should serve to separate the species of the two genera. The majority 
of the characters cited below should hold in all cases. Venationally 
these characters are as follows: 
(1) The very short, usually almost transverse, radial sector of 
Nephrotoma, which in many species is transverse and simulates a 
cross-vein; in other species longer and more oblique, reaching its 
maximum length apparently in species such as vittula Loew. 
(2) The sessile cell M, in Nephrotoma, this being rarely short- 
petiolate. This character has long been known, having been clearly 
stated by Schiner (1864). Species of Tipida vnth the cell sessile 
are unknown. 
(3) The basal deflection of Cui and the cross-vein m-cu at or 
before the fork of M. This character, described for the first time by 
Czizek^ and independently by Brunetti,^ is the nearest approach 
to absolute of any that we have, but even this is approached by 
some specdes of Tipula (the marmorata group, fragilis Loew, ignobilis 
Loew, et al.). 
The male hypopygium of Nephrotoma shows the ninth pleurite 
never completely fused with the ninth sternite, the more generalized 
condition occurring in such species as incurva Loew, where the 
pleurite is almost entirely separated from the sternite, through 
lugens Loew, where the pleural suture is straight and not curved 
dorsally toward the tip, to the more specialized condition with the 
^Tipulidaj Moravicae; Zeilschrift des Mahrischen Landesmuseums, vol. 11, 
p. 50, 1911. 
■'' Fauna of British India, Diptera Nematocera, p. 340, 1912. 
