C. H. TYLER TOWNSEND — BIOGEOGRAPHY OF MEXICO, ETC. 39 
Diptera. — The diptera show very decidedly Neotropical affinities. Out 
of the first lot of 22 species determined by the writer and already pub- 
lished, there are only 4 or 5 that are not strictly Neotropical , and these 
are common to the Neotemper ate and Neotropical regions. In the second 
lot of 22 species, there are 7 species which are Neotemverate as well as 
Neotropical , while all the rest belong to the latter region. The remain- 
ing mass of the diptera, still undetermined, promises, so far as a super- 
ficial examination goes, to fall not far short of this proportion. Those 
species so far determined are here given. Unless otherwise noted, they 
are purely Neotropical. The numbers in parentheses are those under 
which the species were published. 
1. Oecacta furens Poey. — March 5. ISTautla at the mouth of the river. 
This species is known from Cuba, Jamaica, and the Mexican coast from 
Tamaulipas to Tabasco. (1) 
2. Psychoda punctatella Towns, (n. sp.) — March 30. (23) 
3. OTbiogaster tae?iiatus Bell. — June 26. The only other locality 
known is Tuxpango, Vera Cruz (near Orizaba). (24) 
4. Sargus sp. — June 19. Belongs to a Neotropical group. (2) 
5. Chrysops costatus Fab. — March 16. This is the first record from 
Mexico. Known from the West Indies, Guatemala, Nicaragua, and Bra- 
zil. (3) 
6. Hadrus lepidotus Wd. — March 5. Known from Cuba and Mexico 
to Guiana and Brazil. (4) 
7. T alanus mexicanus var. limonus Towns, (n. var.) — July 17. On 
flowers of the Cordia sp. The varieties of mexicanus extend from Flor- 
ida, the Southern U. S., and Mexico, to Cayenne and Brazil. (25) 
8. Leptog aster pictipes Lw. — June 21. Belongs to a group of closely 
allied species occurring from Illinois to Mexico, Cuba, Jamaica, and 
Porto Bico. (26) 
9. Nausigaster meridionalis Towns, (n. sp.). — July 16. On flowers of 
the Cordia sp. Belongs to a small group of Nausigaster occurring from 
the lowlands of Texas through tropical Mexico to Brazil. (5) 
10. Baccha phaeoptera Schin. — March 30. Belongs to a group occur- 
ring from South Florida, Cuba, and the lower Bio Grande through trop- 
ical Mexico to Brazil. (6) 
11. Ocyptamus fuscipennis Say.-— March 2 to April 7. First record of 
the species from Mexico. It occurs from the Atlantic States and Florida 
to Kansas, Mexico, and the West Indies. (7) 
12. Volucella olesa Fab. — July 18. On flowers of the Cordia sp. 
Florida to New Mexico, and throughout the American tropics, as well as 
other tropical countries. (8) 
13. Volucella viridana Towns, (n. sp.). — July 7. On flowers of the 
Cordia. (33) 
