1915] Brues — Netc Wingless Phorid Fly from Jamaica 103 



small, rounded, but distinctly angulate at the insertion of the arista which is very 

 long and delicate, reaching to the base of the abdomen. Head, viewed from the 

 side, twice as long as high, flat above and strongly curved downwards in front and 

 backwards to the anterior angle of the antennal cavity; face obtusely produced for- 

 ward and downward below the oral margin; margin of head below eyes horizontal. 

 Eyes with 15-16 ommatidia. Palpi of moderate size, flattened; with five bristles 

 below and several longer ones at apex. Thorax in dorsal view three times as broad 

 as long on the sides; medially narrowed to half its length at the sides, both the 

 anterior and posterior margins bisinuate; humeri distinctly marked off as rounded 

 tubercles; clothed with sparse fine hairs like those on the head, but without bristles. 

 Abdomen with six fully chitinized plates wliich fully cover its dorsal surface, except 

 where the sutures extend between them as very narrow membranous bands; first 

 plate nearly semicircular, with straight posterior edge; second to fifth subequal in 

 length, the fourth broadest; along the posterior edge each plate has a black band 

 which bears a series of from 15-20 pale circular dots from each of which arises a 

 bristle about one fourth as long as the width of the plate. Sixth plate a little longer 

 than the preceding, rounded behind, and with four fine bristles on its posterior 

 margin; whole abdomen above, finely, sparsely hairy. Ov'ipositor more or less ex- 

 serted, of the usual tubular, soft, fleshy type. Venter with only one plate, that of 

 the sixth segment; this somewhat broader than long, straight in front and on the 

 sides, but' concave behind; posterior margin with four small equidistant bristles, 

 one at each angle with a pair between. Legs stout, hairy, but without distinct 

 bristles, except for a tuft of short ones at the tip of the anterior coxae, a series of five 

 or six on the outer edge of the middle coxae and one at the tip of the hind coxae; 

 front tibiae with one minute spur; middle ones with a larger one and hind ones with 

 a pair of which one Is very small. 



Williamstown, Jamaica, B. W. I. Type No. 9033 in the Muse- 

 um of Comparative Zoology. Described from specimens given me 

 by Prof. Roland Thaxter. 



This species is a close relative of the other forms of Chonocepha- 

 lus which have already been made known from various parts of the 

 world. This great similarity of the species is most remarkable 

 when it is recalled that the others known from females are from 

 such widely separated regions as the Bismark Archipelago, Ger- 

 man East Africa, Sumatra, India, Mexico and Guatemala. On 

 account of their close resemblance I have drawn up a table for 

 their separation. It must be stated, however, that this is in part 

 compiled from descriptions, as I have seen specimens of only three 

 species. 



KEY TO THE SPECIES OF CHONOCEPHALUS (FEMALES). 



1. Dorsal abdominal plates of the first to fifth segments with a series of transparent 

 dots along the posterior border from which arise the marginal bristles 2 



