530 t LIST OF DTPTERA. 



i. Pedes nigri. .... viduata, JVied- 



ii. Pedes pallidi. .... pusilla, Macq, 



D. Thorax niger, humeris et pleuris pallidis. mellipes, JVied. 



E. Thorax niger, limbo luteo. - - xanthopus, Wied. 



F. Thorax niger, scutello fulvo. - - - \\mhi\U, Macq. 



G. Thorax totus pallidus. 



a. Alae apice nigra;. .... melanura, Wied. 



b. Alae fusco maculatae. ... maculipennis, Macq. 



The following groups represent most of the South American 

 species. 



Group 1. 



Corpus metallicolor. Caput et thorax setis nonnullis. Facies 

 valde couvexa. Mystax rarus. Proboscis longa valida, recta. An- 

 tennarum articulus 3us basi apiceque subattenuatus, lo et 2o con- 

 junctim mult<» longior. Pedes validi, pubcscentes ; femora tibiaeque 

 anteriora tarsique subsetosa. 



Head and thorax with a kw bristles. Face very convex. 

 Mystax with a few bristles. Proboscis long, stout, straight. Third 

 joint of the antennae much longer than the first and the second 

 together, slightly tapering towards each end. Legs stout, pubes- 

 cent; tarsi and anterior femora and tibiae slightly bristly. Fore 

 branch of the cubital vein undulating; second nearly straight, re- 

 mote from the first externo-medial ; first and second externo-medial 

 veins straight; third curved abruptly hindward and united to 

 the fourth far from the border. Subanal and anal veins united very 

 near the border. 



Laphria Olbus. 



Group 2. 



Corpus metallicolor, hirsutum et setosum. Facies apud epi- 

 stoma convexa. Mystax setis plurimis. Proboscis valida, lanceo- 

 lata, subarcuata, non longa. Antennarum articulus 3us longifusi- 

 formis, lo et 2o conjunctim longior. Pedes validi, pilosi, setosi ; 

 femora sat crassa. 



Body and legs metallic, rather thickly beset with hairs and 

 bristles. Face convex towards the epistoma. Mystax with nume- 

 rous hairs and bristles. Proboscis stout, lanceolate, rather short, 

 slightly curved. Third joint of the antennae elongate-fusiform, 

 longer than the first and the second together. Legs stout, hairy 

 and bristly; femora rather thick. Fore fork of the cubital vein un- 

 dulating; hind fork and first externo-medial vein slightly curved, 



