1893,] MR. E. E, ACSTEN O'S :yEW DIPTEROUS IlfSECTS. 145 



yellow, pectus aud metaDotiim metallic black. Scutellum brownish 

 yellow. Abdomen: the anterior margin and sides of the first 

 segment pale yellow ; on the second segment a narrow transverse 

 band, slightly notched in the median line behind and situated just 

 beyond the middle of the segment ; third segment with a cres- 

 centic band in the middle, narrowly interrupted in the median line, 

 concave posteriorly, and nearly three times as broad as the band 

 on the second segment ; the sagittate markings are situate on the 

 anterior half of the fourth segment, and directed anteriorly, they 

 are narrowly separated in the median line and are truncated in 

 front by the hind margin of the preceding segment ; on the fifth 

 segment the yellow markings consist of deeply notched bases of 

 arrow-heads, situated one on each side of the anterior half of the 

 segment, the whole of the remaiuder of the arrow-heads being, as 

 it were, hidden beneath the fourth segment ; the inner angles of 

 the bases of the arrow-heads are longer thaix the outer, and the 

 notches are very much larger than in the case of the arrow-heads 

 on the previous segment ; sixth segment wholly purplish black : 

 the markings on the fourth and fifth segments are of a deeper 

 yellow than the others. 7^e(/s yellow ; the posterior femora and 

 tibiae each with two brown i)ands, the band near the base of the 

 femur being more diffuse and less distinct than the others ; similar 

 bands are faintly indicated on tlie middle legs. Wings with a 

 brownish tinge, which becomes concentrated at the tips ; distal 

 half of subcostal cell brown ; third lougitudinal vein straight ; 

 distal portion of fourth vein, closing first posterior cell, short, 

 upright. 



Cinchona, Jamaica ; June ( W. Faivoett, Esq.) i one specimen. 



This species of Bciccha is distinguished from any other known 

 to me, by the shape of the conspicuous yellow markings of the 

 abdomen. 



Baccha signifeba, sp. n. (Plate IV. fig. 8, cf .) 

 S . Length 11^ mm. 



Face and cJieels metallic blue-black, with black pile ; face 

 narrowly shimmering white on the sides above ; facial tubercle 

 sharply defined, conical ; front (including the large antenni- 

 ferous projection) metallic black, with a dull black quadrate 

 median area behiud. The first two joints of the antennce 

 black ; the third brown ; the arista brown. Tliorax dull velvety 

 black on the dorsum, with three stripes on each side of the median 

 line metallic black ; the innermost stripe on each side is very 

 narrow and tapering, and does not reach much more than half- 

 way ; the intermediate stripe is broader, aud also tapers, but fuses 

 posteriorly with the lateral stripe, which is very broad indeed, and 

 extends to the scutellum ; the two outside stripes are divided by 

 the transverse suture ; the lateral stripe includes the post-alar 

 callosity; plmroi metallic bronze -black. Scutellum metalhc 

 black ; thorax and scutellum clothed with short black pile. 

 Abdomen dull velvety black, ivith yellow dots and metallic bands ; 



Peoc. Zool. Soc— 1893, No. X. 10 



