152 MB. E. E. ArSTElf ON NEW DIPTEROUS INSECTS. [Jan. 17, 



tapering somewhat towards the sides and nari-owly di\dded in the 

 median line ; in the median line the baud is about three times as 

 far from the posterior margin of the segment as from the anterior, 

 and it may appear not quite to reach the lateral margins ; on the 

 fourth segment the ochraceous mai-kiugs take the shape of a some- 

 ^\hat lunate mark projecting back« ards from the anterior margin 

 on each side of the median line, with a narrow piece projecting 

 obliquely from the base of each mark towards the lateral margin 

 on each side ; the inner margin of the " lunate " marks is convex, 

 they extend about two-thirds the length of the segment, and are 

 obliquely truncated anterioi'ly and posteriorly ; the extreme base 

 of the segment is narrowly ochraceous from each " lunate " mark 

 to the side ; on the fifth segment the ochraceous marks are re- 

 presented by a stripe on each side of the median line, starting 

 from the anterior and reaching to the posterior margin, with the 

 inner side of each slanting out^^ ards posteriorly, so that the ground- 

 colour between them constitutes a small triangle, which is con- 

 tinued as a narrow median stripe to the anterior margin ; the ends 

 of the two ochi'aceous stripes are connected by a narrow and 

 iudistinctly defined band near the posterior margin ; in addition 

 to this there is a small ochraceous triaugle projecting from the 

 antei-ior margin of the segment on each side, between the stripe 

 and lateral margin, with its base connected with the stripe and its 

 apex situated at rather more than one-third of the length of the 

 segment ; sixth segment with the median two-fourths of its hinder 

 margin occupied by a yellowish band, each end of which is 

 connected with the anterior margin by a short ochraceous stripe. 

 The lateral prominences of the fii-st abdominal segment bear a tuft 

 of ochraceous pile, mingled with blackish pile posteriorly ; the 

 remaining segments are sparsely clothed with very short black pile, 

 wliich becomes somewhat longer on the sides, especially in the 

 case of the fifth segment. 



Brazil, Sautarem (Bates) : one specimen. 



There are also two males in the collection whicli I consider 

 to belong to this species ; but siuce they ai'e in poor condition, I 

 have described the 2 ^^ greater length. 



<J. Length 12| mm. 



llesemhlmj ilie 5 , '-*«' diffenng as follows : — the most stinMnri 

 difference is presented by the coloration of the iviiufs ; these are 

 uniformly suffused with paZe hrown, which, though stronger in the 

 costal and darkest in the subcostal cell, shows only the very faintest 

 trace of concentration at the tip of the submai-ginal cell (none at 

 all in the second specimen in the collection, in w hich the tint of 

 the wings is considerably lighter) ; the luings, therefore, do not 

 present a blotched appearance ; the wings are also considerably 

 narrower, the second longitudinal vein is straighter, and the 

 terminal portion of the fourth vein, closing the first posterior cell, 

 much more oblique : the dark stripe on the thorax, on each side of 

 the narrow median cinereous one, is broader : the abdomen is 

 hrovnier, the marl-ings yelloirer ; second segment yellower at the 



