34 DIPTERA OF NORTH AMERICA. [PART III. 



with Pyrgota and Adapsilia in the want of ocelli, and resembles 

 Adapsilia very much in the structure of the face ; but it differs in 

 the but inconsiderable elongation of the first abdominal segment, 

 in the greater length of the other segments of the female abdomen, 

 aud especially in the long, elongated-conical, but not flattened 

 ovipositor. 



Judging by the figure which Macquart gives of his Toxura 

 maculipennis, I must suppose with a considerable degree of pro- 

 bability, that it likewise belongs in this circle of relationship. 



I have no doubt that the interesting genus Toxotrypana Gerst, 

 if placed in the family Ortalidse, would find its location in the 

 section Pyrgotina, on account of its not flattened ovipositor, its 

 hairy first longitudinal vein, and the small development of its 

 clypeus. The presence of ocelli, the enormous length of the ovi- 

 positor, and the elongation of the posterior angle of the anal cell 

 into a very long lobe distinguish this genus from the other 

 genera of the group in a most marked manner. I have already 

 alluded to the fact that this genus shows some characters which 

 would seem to justify its location not among the Ortalidee at 

 all, but among the Trypetidse of the group Dacina. 



Mr. Macquart has established the genus Heterogaster for a 

 South-African species. As the name he gave to this genus was 

 preoccupied a long time ago, I replace it by the name of Spheno- 

 prosopa. This genus is very like Adapsilia in the structure of 

 the head ; in the profile it projects considerably in front of the 

 eyes : the middle of the face forms a high and straight ridge 

 descending perpendicularly ; alongside of it the antennal fovese, 

 which are further from the middle than usual, descend perpendi- 

 cularly to the edge of the mouth. The cheeks are very broad. 

 The oral opening is very small, the clypeus but little developed, 

 and the proboscis not incrassated. Sphenoprosopia differs from 

 Adapsilia, Pyrgota, and Hypotyphla by the presence of distinct 

 ocelli, the great elongation of the third antennal joint, which 

 nearly reaches the edge of the mouth, the enormous development 

 of the last segment of the abdomen of the male, very approxi- 

 mated cross-veins, very parallel longitudinal veins, and a not 

 acute posterior angle of the anal cell. The first and third longi- 

 tudinal veins are distinctly bristly. I have no doubt that 

 Sphenoprosopa belongs to the Pyrgotina, although, on the 

 other hand, I must acknowledge that several of the above- 



