E. T. CRESSOX, JR. 
63 
N. triangulifera Schiner 
1868. Rcise Novara, Dipt., 241, (South America) 
The description of this species suggests affinities to olivacea in 
the black antennae and tibiae, and the abdominal spots in 
two series. I do not know of ain'- non-vittate Agrolimna from 
South America. On the other hand it may l>e allied to the species 
of the cinerea group, near loewi or biseriata, or, not improbably, 
allied to jloridensis. 
N. transversa Walker 
1856. Dipt. Saund., i, 407, (United States). 
Reference to this species may be found under furcata. 
N. unicolor Loew 
1862. Mon. Dipt. N. Amer., i, 137. 
See loewi. 
N. varia Jones 
1906. Univ. Cal. Tech. Bull, i, 1.53, (California). 
Simony in of erythrocera. 
DICHAETA M eigen 
1830. Dichaeta i\I eigen, Syst. Beschr., vi, 61. 
This genus was originally liased on the spinose development of 
the apical abdominal segment of the male. As this character is 
not of generic value, we have to resort to other less marked char- 
acters. It is not an altogether satisfactory genus, Imt I have 
been unable to find any tendency to intergrade with its allies. 
The only possible apparent associate is ParoHmna decipiens, a 
possibility which should not be overlooked. As the species are 
known at present there is no trouble in limiting the genus. 
It is placed with N^otiphila in the group Xotiphilae, and may 
be distinguished from that genus bj" the dark color and more 
shining abdomen of its species. Structurall}" it is distinguished 
by the stronglj^ developed proclinate frontal orbital bristle, and, 
as suggested b}^ Becker,- by the form of the facalia, which are 
hardly distinguished as longitudinal areas, l)ut more as a ridge, 
so that the bristles are very close to the parafacial grove, while in 
Notiphila these bristles are separated from the grove l)y the full 
width of the broad facalia. Regarding the development of the 
^ Berk Eiit. Zeit., xli, 105, (1891). 
TR.\xs. A.M. p:nt. soc., xliii. 
