86 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
The venation is the normal one for the family. There seems to be 
more individual variation in this genus than in Psilocephala; cell M-8 
may be closed or open in the same species, or closed in one wing of a 
specimen and open in the other. R—4 is never sharply curved. In 
some species the wings are generally infuscated or spotted, in the 
majority of species hyaline, or the cross veins clouded. 
In the following tables of species Walker’s three species—varia, 
nervosa, and senex—are not included because it is impossible to 
identify them with certainty at present. Although the female of 
T. strigipes is well marked, I have seen only one poorly preserved 
male, which I have described. In the table of females anomala 
Adams, nigra Say, and bolbocera Osten Sacken are omitted, the first 
two because of inadequate descriptions. 7. crassicornis Bellardi and 
T. ruficornis Macquart are not included in the tables; the first species 
may be recognized some day from Mexican material, but the de- 
scription of the latter is too brief to identify the species. 
TABLE OF MALES.10 
1. Small, Psilocephala-like species, the abdominal tergites rather flattened and 
* silvery pollinose..........- SAE sas aes BASE ea 
Species over 6 mm. in length: ne Etavwes eonieat: in poet pins and not 
silvery ‘above se 12 O22 2 BO OO eA PE eee 
2. Wings with two haw cabin 2 LL di. Lee ess. fanomalai Adame! 
Wings hyaline........-. - $20: -bee 49 Oe 
3. Sides of the seconds to fifth abdominal Menon piaiae black; Mont legs s wholly 
black. . eles --..-.-- Dygmaea, new species. 
Sides of the abdomen pray palin: ont tihiae except the apex and the tarsi 
yellow... oom .....-- Melanoneura Loew. 
4. Abdomen Hien a ytena ce el elothed aaith white or silvery white pile; (in 
the female the frons dull pollinose)..........--.-.- aqgt te led teas 
Abdomen not colored thus (in the female Sein a sara ‘alles on the frons, 
or one or more shining marks). . Lee 2: So cae allt 
5. Bristles of head and thorax vallowiah White: ome y yallowich southwestern 
species. ..... 2 OF rue SAS semitaria Coquillett. 
Bristles of head isuallyy black, Toe a the ihortte lacie SYGATE 6. 
§.,, Remora yellowashann #4 tee ee ae Soh. esha eae _ bella aohen 
Femora black........- atic eis Lee ee ee See pea 
7. Pile of head and thorax entirely ages Eee pnciica, new species. 
Pile of head and thorax largely white or yellowish... : ae cee eee 
8. Wings hyaline or whitish, without clouded veins or dark peelenes OSU a 
Wings with veins:bordered:or:spotted= 5124 2220-2 eee o2a. 2 Uo es 
9. Tips of the femora yellow; eastern nae sere spe eegtiieachores ates candidata Loew. 
Femora black to the tips. . Z aya ne cee, 
10. Bristles of vertex and Bcomee -aillemls eae ‘western precieg 
novella yee 
Bristles of vertex and occiput black........- (2E eee 
11. Fronswith a hemispherical black eallonitys antenhaé with lack ‘ail: 
californica Krdéber. 
Frons without callosity, gray pollinose; antennae white pilose............- 12. 
10 Four species described by Kroéber in his 1914 paper are not included, the writer knowing of only 
one species when submitting this manuscript. 
