170 C©. R. Osten Sacken: 
The legs of the Tipulidae are comparatively much longer than 
those of the other families of Diptera nemocera (except perhaps 
the BDlepharoceridae); but the coxae are never so long as in the 
Mycetophilidae, the femora never dentate, as in some Ceratopogons; 
the tibiae and tarsi never bearded as in some Ohironomi; nor do 
the last tarsal joints and the ungues offer those structural modifica- 
tions which distinguish many Ceratopogons. In general, apart from 
the presence or absence of spurs, of empodia, of denticulations of 
the ungues, and from the proportions between the length of the whole 
limb and its different parts, the legs of the Tipulidae offer but little 
to make use of in a generic or specific description. 
In size, the majority of the Tipulidae are considerably larger 
than the other Diptera nemocera, and the contrast in this respect 
is very striking. 
The only genus which gave rise to discussion as to its being a 
Tipulid or not, is Dixa. It was referred to the Mycetophilidae 
by Meigen and Zetterstedt; to the Tipulidae by Macquart and 
Westwood; Ropdani connected it with Trichocera and Haliday pla- 
ced it provisionally, together with Orphnephila, in the artificial 
group Heteroclitae. Dixa has no thoracic suture; the ovipositor 
of the female, according to Haliday, is different from that of the 
Tipulidae, consisting of two short, broad, round lamels; the pre- 
sence of only six longitudinal veins, the shortness of the auxiliary 
vein, the absence of both subcostal and marginal crossveins, the 
absence of the discal cell ete., constitute a type of venation which 
separates Dixa from all the known Tipulidae. The rather extra- 
ordinary larva of Dixa is one ground more for separating this 
genus. Altogether I incline to the opinion of Haliday in leaving 
Dixa in an isolated position. 
II. Chronological list of the genera of Tipulidae published since 1867. 
(Supplement to the List in Monogr. N. Am. Dipt. Vol. IV, p. 13—17) 
Furina Jaennicke 1867 (Eriopterina); preoce. Dumer. Rept. 1853. 
Liogma 0. Sacken 1869 (Cylindrotomina). 
Longurio Lw. (Tipulina) 1869. 
Lipsothrix Lw. (Eriopterina) 1873. 
Eutonia v. d. W. (Limnophilina) 1874. 
Semnotes Westw. (Tipulina) 1876. 
Libnotes Westw. (Limnobina) 1876. 
Phyllolabis O. S. (Limnophilina) 1877. 
Diotrepha O. S. (Limnobina anomala) 1878. 
