396 CHARLES T. BRUES. 



in scarcely need mention that the post-embryonic devevelopment is 

 not a good character to separate groups, while the shape and posi- 

 tion of the antenna! cavity are characters which appear in such an 

 endless combination that we are always open to error in attempting 

 an artificial division of groups on such a character. 



In my opinion the peculiar antenna? of Termitoxevia are enough 

 to prove without a doubt its close relationship to the Phorida?. The 

 Phorida? are absolutely unique among the Diptera by the structure 

 of the antenna? which have the second joint enclosed in the third. 

 Termitoxenia has exactly similar antenna?, both in shape and struc- 

 ture. We must then consider the two closely related or believe that 

 the similarity is purely accidental, which is scarcely possible. The 

 comb-like rows of bristles upon the metatarsi of Termitoxenia are 

 also exactly similar to those of many Phorida?, in which family the 

 tibia? and tarsi show a great tendency to bear such rows of hairs. I 

 know of no other Diptera which possess these. Then the shape of 

 the thorax, the form of the legs, with the long free anterior coxa?, 

 the reduction of the wings and the eyes, the swollen abdomen, with 

 a very small first and extremely large second segment, all find their 

 counterparts among certain Phorida?. The probosis has no doubt 

 been greatly modified to conform with its termitophilous habits. 



For these reasons I have included Termitoxenia in the present 

 paper. While it may represent a distint family, it is evidently 

 closer to the Phorida? than to any other Diptera. 



CATALOGUE OF SPECIES. 

 As many of the generic names used in the present paper are new 

 and necessitate a different arrangement of the species, I have prepared 

 i he following catalogue in which the species are segregated in their 

 proper genera. North American species are in the larger type, 

 others in the smaller. 



1*11 OK \ Latr. 



pachyneura Loew, Centuries, vii, 97 (18o'6). 



fratercula pp. nov. 



thoracia Meig.. ("hiss i, 313, 2. 



microcephala Loew, Centuries, vii, 9fi. 



spinipes Cog.. Canan". Ent., xxvii. 105. 



olymplse sp. nov. 



scutellatas sp. nov. 



multiseriata sp. nov. 



venusta Coq., Canad. Ent., xxvii, L05 (1895). 



