1916.] NATUKAL 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 nyctops, 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 R 2 long, not tending to be oblique, deflection of R i+b 

 nearer the wing-root than is r-m, basal deflection of Cih nearer to the 

 base of cell 1st Mi, etc.; from the lenta group it differs in the long 

 sector; from emmelina, it differs in the petiolate cell R 2 , and from 

 noveboracensis it differs in having Rs almost in a line with R 2 ^ 3 , the 

 dark brown stripes on the praescutum, etc. 



POLYMERA Wiedemann. 



Polymera Wiedemann; Diptera exotica, vol. 1, p. 40 (1821). 



Polymera georgiae Alexander. 



Polymera georgice Alexander; Psyche, vol. IS, pp. 199, 200, PL 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 georgice 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 (J uncus Roemerianus). The forest cover con- 



