1916.] NATURAL SCIENCES OF PHILADELPHIA. 535 
the caudal margins a little brighter; eighth and ninth sternites dark 
brown. 
Habitat. — Northeastern United States. 
Holotype, d" , Mountain Lake, Fulton County, New York, altitude 
1,600 feet, June 13, 1916 (Alexander). 
Paratopotypes, 2 cf 's. 
Type in the collection of the author. 
This species was associated with Erioptera nydops, and an account 
of the ecological conditions and associates will be found under the 
account of that species. 
L. Sylvia is quite distinct from any of the described species that 
lack cell Mi of the wings. From the quadrata group it differs in 
having vein R2 long, not tending to be oblique, deflection of /?4+6 
nearer the wing-root than is r-m, basal deflection of Cih nearer to the 
base of cell 1st M2, etc.; from the lenia group it differs in the long 
sector; from emmelina, it differs in the petiolate cell R2, and from 
novehoracensis it differs in having Rs almost in a line with J?2+3, the 
dark bro^^^l stripes on the prsescutum, etc. 
POLYMERA Wiedemann. 
Polymera Wiedemann; Diptera exotica, vol. 1, p. 40 (1821). 
Polymera georgise .Alexander. 
PoUjmcra georgice Alexander; Psyche, vol. 18, pp. 199, 200, PI. 16, fig. 5 
(1911). 
This is the only known species of the genus as yet found within 
our limits and, so far as known, it is confined to the southeastern 
United States. P. obscura Macquart, of northern South America 
and Middle America, ranges into Cuba and may appear in the 
Miami section of Florida. P. geniculata Alexander of Porto Rico is 
also regional. The distribution of Polymera georgim is as follows: 
South Carolina, Georgetown County, South Island, August 19, 
1915 (Alexander). 
Georgia, Decatur County, Spring Creek, July 20, 1912 (Bradley) ; 
Glynn County, St. Simons Island, April, May, 1911 (Bradley), the 
type-locality; Charlton County, Billy's Island, Okefinokee Swamp, 
June 20, 1912 (Bradley). 
Florida, Dade County, Biscayne Bay (Slosson). 
The only specimen that I have ever seen alive was taken in a salt- 
marsh palmetto association on South Island, South Carolina, at the 
east end of the causeway between South and Cat Islands. The 
association was a palmetto island surrounded on the west by a perfect 
sea of the salt rush (Juncus Roemerianus) . The forest cover con- 
