1910] Melander — The Genus Tachydromia 53 
Bay Territory. I do not think this is so. Bimaculata is a much 
smaller species with white palpi, and is rare. The only specimen I 
have seen is the type from Alaska. I take it however that maculz- 
pennis is the same as our common pusilla Loew. I have examined 
over fifty specimens of this species from Massachusetts, Wisconsin, 
Illinois, Missouri, and South Dakota. Since it is so widely distrib- 
uted in the States it probably occurs in Canada also. The rest of Mr. 
Walker’s Tachydromias I can not decipher. They may belong to 
Tachypeza or to the present genus. Osten Sacken listed vicarius as a 
Platypalpus. ‘The two-line description reads that the legs are slender 
which raises more doubt as to what the species really is. 
Table of the North American Species of Tachydromia. 
1. A white glistening pruinose spot between the front coxae and the humeri, 
rarely absent: wings with two dark bands: the distance between the 
two cross veins more than twice the length of the hind cross vein: 
ALIS HNL OMIMMUN A oe. Teka veis) ophhcte te, cits tide, ota ce laps aon cede a tareerie canes o Reems tolialls oes 
No glistening spot on the pleurae: wings with a single brownish subapical 
cloud or hyaline; cross veins separated scarcely more than the length 
Ol the shine) icross veim': anistay subterminal... .0 400 eee ee): © 6. 
2. Palpi and halteres black: marginal cell obliquely truncate 
enecator Melander. 
Palpi and halteres paler: marginal cell rounded at theend.......... 3. 
3. Dark cross bands united along the costa........ varipennis Coquillett. 
DankAcross) bandsvseparatedey .. editor wlccietale.s ocreclale avatevcretenete tans 4, 
4. Wings blunt, fringed with comparatively long hairs: propleurae not 
POEUMM OSC Hate-c Hie B0/4 AEF Seats aes hve MAS ciliata sp. nov. 
Wings slender, the marginal hairs short: propleurae pruinose........ 5. 
oa) duegs nearly uniformly dusky). a... e-sateis cole schwarzii Coquillett. 
Base of legs pale yellow, outer portions in part black. 
schwarzii var. diversipes. var. nov. 
6. Palpi black: wings with a broad subapical cloud. 
maculipennis Walker. 
alpimyellowisheswangsumcloudederts. 1:1. :crst-tele steieiecetloleye etets were liote Ue 
7. Thorax shining, humeri prominent: palpi narrow.................. 8. 
Thorax and abdomen sub-glaucous, humeri smaller...............- 9. 
8. Third and fourth veins divergent...... simplicior Wheeler & Melander. 
fhicd and fourth vemssubparallel:. 0.0.1. eiteait ie. calva sp. nov. 
9. Palpi long and narrow: scutellum with four bristles: antennae reddish 
insularis sp. nov. 
Palpi broader: seutellum with two bristles... 00.6066. sea eee 10. 
10. Acrostichal and dorsocentral bristles present: legs slender piceous, 
antennaen bb lackesrrs mae atet ar econ erste ate elenafeslereaatae agens sp. nov. 
Middle of dorsum without bristles: base of legs and of antennae yellow, 
fogt rarssilgolme WR Char ie cade < 2 66's os eclee 6s ohsie's universalis sp. nov. 
