42 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 6!> 



This species is of northwestern distribution: British Columbia, 

 Vancouver Island, Washington, Oregon, Idaho. 

 Type. — In U. S. National Museum. 



SOUTH AMERICAN XYLOTINI IN THE NATIONAL COLLECTION 



KEY TO GENERA OF SOUTH AMERICAN XYLOTINI 



A'. Metastei'num pilose. 



B\ Hind femur witli one or two apical toothlike processes ventrally. 



C^. Hind femoral process consisting of one tooth ; hind coxa without 



spur (OrtJiolophus Bigot?) Tropidia Meigen, 



C". Hind femoral process hidentate ; hind coxa with small spur. 



D\ Body vei"y elongate ; discal cross vein simple ; males holoptic. 



Acrochordonodes Bigot. 

 D^ Body broad ; discal cross vein with a free-ending branch ; males 



dichoptic Stilbosoma Philippi. 



Bl Hind femur without apical process ; face subcarinate. 



C\ Wings nearly devoid of villi, glassy in appearance; arista shorter 



than width of face Syritta St. Fargeau & Serville. 



C^ Wings villose, not glassy ; arista distinctly longer than width of face. 



Planes Rondani, 

 A^ Metasternum pubescent or bare. 

 B\ Body dark colored. 



C^ Face black, with a longitudinal median ridge and two oblique 

 ridges. 



D\ Abdomen strongly constricted basally Tatuomyia, new genus. 



D^ Abdomen of nearly uniform width Crepidomyia, new genus. 



C^ Face bright yellow with an obtuse longitudinal ridge ; metathoracic 

 spiracle distinctly larger than third antennal joint ; hind tro- 

 chanters of male spurred Sterphus Philippi. 



C'. Face bluish-black, gently concave in profile ; metathoracic spiracle 

 much smaller than third antennal joint; hind trochanters simple. 



Philippimyia, new genus. 

 B^ Body entirely reddish yellow ; very large and robust__Eriophora Philippi. 



Genus ORTHOLOPHUS Bigot 



The type specimen of Ortholophus notatus, was described by 

 Bigot as having the hind femur less swollen than in Syritta and not 

 spinose beneath. This character would be sufficient to exclude the 

 species from Tropidia. 



The same specimen now lacks the legs, which presumably were 

 broken off since the time the species was described, as definite men- 

 tion was made of the legs. The head was also broken off but glued 

 onto the specimen again. It is of the same type found in Tropidia 

 nigricornis Philippi (described below) and certain other charac- 

 teristics of the body definitely ally it to Tropidia. 



ORTHOLOPHUS NOTATUS Bigot 



Description based on type specimen. 



Male. — The facial carina is more sharply defined than in any other 

 species of Syrphidae except T. nigricornis Philippi. A small por- 



