1893.] MR. E. E. AFSTEX OX XEW DIPTEEOUS INSECTS . 149 



triangle long, narrow, cinereous polliuose. Front in the ? , except 

 the posterior third, A\-hich is cinereous pollinose, pale shining yel- 

 low, with a blac]cish-bro\AU dot in the centre line above the base 

 of the antenna^, from ^^•hich a narrow brown median stripe runs 

 back to the pollinose portion : ocelli remote from the vertex in 

 both sexes. Antennce yellow, third joint rounded at the tip; arista 

 black. Occiput cinereous pollinose. The median cinereous polli- 

 nose stripe on the thorax is much narrower, and also somewhat 

 longer, than the lateral ones, but all the stripes terminate at a 

 considerable distance from tlie seutelhim : front portion of the 

 pleurcT metallic yellow ; pectus, posterior portion of the pleurre, 

 and metauotum steely black. Scutdlmn yellow ; a narrow stripe 

 along the anterior margin, tapering towards the sides, which it 

 does not quite reach, black. First segment of the ahdomen with a 

 dark brown posterior border, the lateral protuberances with a tuft 

 of yellow pile ; second segment with the anterior and posterior 

 thirds (in the typical c5" rather more than the anterior third) dark 

 brown, so that the )"ello\\' ground-colour is restricted to a baud 

 across the middle ; this may appear to be narrowly divided in the 

 median line ; third and fourth segments with, the hind margin, 

 the median third of which is expanded (considerably so in the 

 typical (j* ), a quadrate area occupying each posterior angle, a some- 

 «hat clavate mark projecting inwards and forx^ards from these, and 

 a median narx'ow stripe dark brown ; in the typical $ the median 

 stripe does not quite reach the anterior margin of the segment, 

 while the " clavate " markings are narrower and less clavate than 

 in the S : in a second S in the collection the median stripe is 

 much broader, and also does not quite reach the anterior margin ; 

 on the fifth segment the markings are precisely similar, except 

 that the brown posterior margin and the quadrate areas in the 

 posterior angles are almost obsolete, and that (in the typical speci- 

 mens at least) the median stripe reaches the anterior margin of the 

 segment in both sexes : sixth segment yellow. Third longitudinal 

 vein of the wings somewhat sinuate, convex forwards above the 

 distal half of the first posterior cell ; terminal ])ortion of fourth 

 vein bounding the first posterior cell only slightly oblique ; pos- 

 terior cross-vein straight. 



Bx'a/il, region of the Amazons {Bates) : three specimens. 



This species is distinguished by its size and markings from any 

 other knowii to me. 



Group 11. 



Bacciia siiiACEA, sp. n. (Plate Y. fig. 13, S .) 



(S . Length 10 mm. 



Thorax dull, clothed with lUitue pidloi of pale sienna colour, ivith 

 narrow leaden stripes ; a somewhat sharjili/ defined median pyriform 

 area on the pectus (/reenish hronze ; abdomen Jl<(ttrned, hut little Con- 

 tracted basallif, rufous ochraceous, with oranrje-ochraceous stripes ; 

 front with an ohtuse antenniferoas projection, marked ivith a round 

 blach spot : aluhc of full size. 



