HOUGH: SOUTH AMERICAN MUSCID.E. 213 



ties are small and almost parallel ; the lesser ©cellar, including 

 the postvertical, very tiny. The inner verticals are large, the 

 outer verticals smaller but distinct, and the occipito-central of 

 good size. The cilia of the posterior orbit are shorter than in 

 the female, and I can see but one row of bristles on the occipital 

 surface parallel to them. The posterior orbit is white pollinose 

 and, as is usual in the male, its dorsal half is obliterated by the 

 greater development of the eye. 



The front of the female is about one-fourth as wide as the 

 head (0.7 mm. and 2.7 mm.). The vitta is about one-third 

 the width of the front and is of a dark brown color with more 

 or less of a reddish tinge. It is somewhat narrower towards 

 the antennae and broader towards the vertex. The ventral two- 

 thirds of the geno-vertical plate is yellow pollinose, the dorsal 

 third polished black or brown, and only with a particularly 

 favorable incidence of light looks even thinly pollinose. There 

 are about eight transfrontal bristles and laterad these, at the 

 usual level, two or three small proclinate orbitals. On the dor- 

 sal third of the geno-vertical plate are also a number of minute 

 hairs. The vertex is polished black or bi'own. The great ocel- 

 lar bristles are of fair size : the lesser ocellars. including the 

 postverticals, number from four to six pairs. The inner and 

 outer verticals are normal, the occipito-central long, and the 

 occipito-lateral is not present. The cilia of the posterior orbit 

 are black and form a complete, well-aligned row. Parallel to 

 the latter, on the occipital surface, I can see at least the begin- 

 nings of two more rows of small bristles. The posterior orbit 

 is yellowish-white pollinose. 



The antennu' and the base of the aristal rachis are yellow, 

 varying in different individuals toward orange yellow or brown- 

 ish yellow. The tip of the rachis and the hairs of the arista 

 look black. The third joint of the antenmr is about twice as 

 long as the second, and the arista is longer than the second and 

 third joints together. The palpi are yellow. 



The thorax is metallic blue, green, or violet, with a very 

 broad, distinct median pollinose band, which begins at the 

 cephalic border and does not reach caudad beyond the trans- 

 verse suture. A similar btit much fainter pollinose band can 

 be seen on and just dorsad each humertts. Looked at with a 

 very strong light and very obliqtiely, these bands seem much 



1.5-K.U.Qr. A-ix 3 



