THE CANADIAN ENTOMOLOGIST. 101 



maxillary palpi 6-jointed, the second and the last joint longer than 

 joints 3-5 ; labial palpi 4-jointed, 



short Hemithynnus, Ashm., gen. nov. 



(Type Thynnus hyalinatus, Westw.) 



15. Maxillary palpi 6-jointed, long, the joints, except the first, which is 



very short, long, subequal, the last joint the slenderest and a little 

 the longest ; labial palpi 5-jointed. (South 



America) Elaphroptera, Guerin. 



(Type Myrmecodes dimidiatus, Hal. 



16. Hypopygium ending in three small, equal or nearly equal, triangular 



teeth, rarely with the middle tooth much longer than the lateral, or 



spined 17. 



Hypopygium ending in three small, equal, rounded lobes 19. 



17. Clypeus subproduced and anteriorly emarginate, excised or 



bidentate 18. 



Clypeus produced, trapezoidal, the anterior margin truncate, never 

 emarginate or excised. 



Abdomen elongate, subcylindrical, smooth, shining, spotted with 

 yellow, much longer than the head and thorax united ; first 

 joint of flagellum only about half the length of the second ; 

 hypopygium at apex 3-spined, the middle spine the 



longest. (Australia) Aeolothynnus, Ashm., gen. nov. 



(Type A. multiguttatus, Ashm.) 

 iS. Abdomen oblong-oval or fusiform, longer than the head and thorax 

 united, the segments banded or maculate with white or 

 yellow. (South America). . . . Pseudelaphroptera, Ashm., gen. nov. 



(Type Elaphroptera Spinols, Sauss.) 



19. Clypeus broadly, semicircularly emarginate anteriorly, leaving a deep 



concave space ; metathorax with two deep impressions or short 

 furrows at apex ; maxillary palpi long, 5-jointed, the first joint 

 short ; maxillary palpi 4-jointed ; abdomen elongate, narrowed 

 towards base, shining, but microscopically shagreened. 



(South America) Pycnothynnus, Ashm., g. nov. 



(Type Elaphroptera atra, Guer. 



20. Third cubital cell, along the cubitus, shorter than the second or no 



longer 21. 



Third cubital cell distinctly longer than the second 22. 



