March, 19 1 1.] FeLT : GENERIC SYNOPSIS OF ItONID.E. 49 



anal segment and a circular, oval or angulate anal orifice with its 

 long axis transverse or at right angles to the median line; ventral 

 surface with disk-shaped pads or folds. South America. 



Tribe ITONIDINARL^. 

 The more characteristic members of this tribe are easily distin- 

 guished by the long, thickly haired antennae with 14, rarely 12 or 

 more segments, the flagellate segments of the male usually binodose 

 and with two or three circumfili, the latter usually with greatly pro- 

 duced loops ; palpi uni- to quadriarticulate ; claws simple or toothed. 

 A very large tribe, including many diverse forms. 



Group BiFiLi. 

 This group is easily recognized by the presence of but two cir- 

 cumfili on the flagellate antennal segments of the male, the nodes 

 being equal or nearly so. 



Genus AMETRODIPLOSIS Riibs. 1910, type Clinodiplosis thalictricola Riibs. 

 Separated from all other genera in the bifili group by the proxi- 

 mal antennal segments of the male being binodose, the distal segments 

 with but one node. Europe. 



Genus LOBOPTEROMYIA Felt 1908, type Contarinia filicis Felt. 

 Antennal segments 14, the basal portion of the stem on the flagel- 

 late segments of the male rarely with a length equal to its diameter; 

 palpi quadriarticulate, easily recognized by the wings with the pos- 

 terior area greatly produced and broadly rounded. North America. 



Genus EROSOMYIA, new genus, type E. mangifera, new species.* 

 Male. — Length, 0.8 mm. Antennae about twice the length of the body, 

 thickly haired, light yellowish brown; 14 segments, the fifth having the basal 

 portion of the stem with a length about three fourths its diameter, the distal 

 part with a length three and one half times its diameter, the enlargements sub- 

 globose, each with a sparse subbasal whorl of setie and a well developed sub- 

 apical circumfilum, the loops of the latter extending nearly to the middle of 

 the following enlargement ; terminal segment with the distal enlargement ovate 

 and apically with a short, stout, tapering process. Palpi : first segment irregu- 

 larly subquadrate, the second a little longer, stouter, the third one half longer 

 than the second, more slender, the fourth a little longer and more slender than 

 the third. Mesonotum reddish brown, the yellowish submedian lines sparsely 

 hairedv Scutellum and post-scutellum yellowish. Abdomen a nearly uniform 

 yellowish. Wings hyaline, broad, the anal angle somewhat produced. Costa 



*Erosomyia mangiferae, new species. 



