MAY FLIES AND MIDGES OF NEW YORK 113 



diameter, with five distinct and separated joints; the first joint 

 short, cylindrical, cut obliquely from without to within, the 

 last joint as long as the third and fourth together, with trun- 

 cated base and rounded tip. The antennal joints are provided 

 with hairs, the last with longer and stouter ones. The fifth joint 

 in certain specimens appears to have a suggestion of a division 

 simulating a sixth joint. The epistome is prolonged, triangular, 

 and truncate. The palpi not more slender than the antennae, 

 have four joints, the last joint being one-half as long as the one 

 preceding. The thorax is prodnced over the head, the humeri 

 are prominent, the center of the thorax is arched, and widens 

 out to the abdomen. The scutellum is triangular with truncated 

 apex. Legs. — Anterior coxae are prominent, first pair is some- 

 what separated from the following pair, the femora are com- 

 pressed and widened; the tarsal claws with a little subapical 

 tooth and two pulvilli. The wings are stumpy, in the form of a 

 flattened racket, more or less developed according to the speci- 

 men. Halteres are wanting. The abdomen is 8-segmented; in 

 the male it terminates ventrally with a large plate carrying two 

 lamellae covering the genitalia; with the female these organs are 

 hidden in the abdomen. Translation from the original. The 

 genus was erected for two Patagonian species, B. antarctica 

 and B. magellanica. 



Genus 11. Eretmoptera Kellogg ' 

 Biol. Bui. 1:82. (P1.35, figs. 15 to 24) 

 Under this name Professor Kellogg published a description 

 of a maritime fly which bears such a resemblance to the genus 

 Psamathiomyia Deby that 1 at first considered them 

 synonymous. There appear to be, however, several characters 

 which may be of suflQcient importance to separate them generi- 

 cally. In Eretmoptera the maxillary palpi are four-seg- 

 mented, while in Psamathiomyia they are two-jointed ; 

 the female of the former has four-jointed antennae, while both 

 sexes of the latter have six-jointed antennae. The remaining 

 distinctive characters seem to be of specific rather than of 

 generic value. The flies were collected December 27, 1898, by 

 Mr J. C. Brown at Point Lobos, a rocky point on the Pacific 



