194 ©. R. Osten Sacken: 
3. Mesocyphona O. Sack. ]. c. p. 152, Tab. 4, f. 15, forceps; 
Western Diptera, p. 199. Represented by three north-american species. 
The discovery of the californian species proved that in my definition 
of this group I had laid too much stress on the forking of the third 
or fourth vein in the formation of the discal cell. Mesocyphona 
‚fossarum Loew, Beschr. Eur. Dipt. III, p. 51 (from Meseritz, Prussia) 
does not seem to belongs here but I am not prepared at present to 
assign it any other place. 
4. Erioptera sensu stricto; O. Sack., 1. c. p. 151, Tab. 1, 
f. 16, wing, Tab. 4, fig. 20, forceps. (Syn. Chemalida Rondani, 
Prodr. 1, p. 180, 1856; Trichosticha, Schiner, Wien. Ent. Mon. 1863, 
p. 221; Fauna Austr. II, p. 538 (ex parte). 
Europe and North-America; contains the bulk of the species of 
Erioptera Meigen. The early stages of .E. lutea and flavescens 
have been described by Beling, Verh. Zool. Bot. Ges. 1878, pag. 50 
and 1886, p. 192. 
Chemalida Rond. as far as I can judge from his very brief 
indications, coincides with Erioptera in the narrower sense; the 
description of the seventh vein settles this point: „undulata et longa 
ut areolae basilares® (Prodr. ete. I, p. 180, line 3 from top). 
Trichosticha Schiner is not a well conceived genus, containing 
besides the true Eriopterae, species of Acyphona, Lipsothrix and 
Oheilotrichia. 
5. Cheilotrichia Rossi, Syst. Verz. Oesterr. Dipt., Wien 1848. 
Mr. Verral (Ent. M. Mag. Oct. 1886, p. 118) places the european 
Erioptera imbuta (Synon. EP. cothurnata Macq. Dipt. du Nord etc. 
I, p. 161) in the subgenus Acyphona, and he is right in so far as 
the venation shows some relationship to that group. But E. im- 
buta differs from all Eriopterae, even in Meigen’s sense, in the po- 
sition of the subcostal crossvein, which is placed at the end of the 
auxiliary vein, and not at a considerable distance from that end, as 
is the case in all Eriopterae in Meigen’s sense. I may be mistaken, 
but I consider this character as important. Other differences from 
Acyphona are found in the structure of the forceps, which has very 
long basal pieces and proportionally developed, long, slender horny 
appendages; the origin of the second vein is much less near the root 
of the wing; the very short submarginal cell, and the marginal cross- 
vein, inserted before its proximal end, remind of the venation of 
Empeda. 
These differences induce me to revive the name Cheilotrichia, 
proposed by the austrian dipterologist Rossi for E. imbuta together 
