i 4 4 R - w - CROSSKEY 



- Facial ridges invisible in profile or only slightly visible at lower end. Scutellum 



with one pair of lateral setae and with the subapical setae inserted well apart 

 (distance between their bases nearly as great as that between a subapical seta and 

 its corresponding basal seta or nearly so). Ocellar setae present. [Not such 

 forms, length under 10 mm.] .......... 6 



6 Abdominal Ti + 2 with median marginal setae. Wing with normal goniine 



venation, m-cu meeting vein M at a point much nearer to the bend than to r-m, 

 distance from m-cu to bend not greater than the length of m-cu. Cell /? 3 open. 

 Facial ridges rather weakly setose only on lower half . LYDELLINA Yilleneuve 



- Abdominal Ti + 2 without median marginal setae. Wing with m-cu meeting vein M 



at a point mid-way between r-m and the bend or at least further from the bend 

 than usual, distance from m-cu to bend slightly to much greater than the length 

 of m-cu. Cell R h closed or virtually so at the wing margin. Facial ridges strongly 

 setose on almost all their height . . . PROSOPODOPSIS Townsend (part) 



7 Second costal sector haired ventrally. Last section of vein Cu 1 subequal in length to 



m-cu. i + i (or ? 2) acrostichal setae .... SUENSONOMYIA Mesnil 



- Second costal sector bare ventrally. Last section of vein Cu x much longer than 



m-cu. 3 + 3 acrostichal setae . . . PROSOPODOPSIS Townsend (part) 



APLOMYA-PHR YXE-group 



Head shape normal, at most only slightly more triangular than usual (Cossidophaga). Eyes 

 bare or haired. Facial ridges bare or weakly setulose, not or only slightly visible in profile. 

 Parafacials bare (except in Pseud alsomyia) . One or two pairs of reclinate orbital setae. Upper 

 occiput flat or swollen, with or without black setulae behind the postocular row. $ without 

 proclinate orbital setae [Mesnil records one pair in Pseudoperichaeta monochaeta Mesnil, not 

 seen]. Arista normal, usually not thickened on more than half its length, basal segments 

 short or at most second segment slightly elongate. Humeral callus with a basal row of three 

 setae in line, with or without additional fourth seta set forwards. 3 + 4 dc setae. Three or 

 four stpl setae (rarely only two). Wing cell 7? 5 open. Bend of vein M moderately strongly 

 abrupt, sometimes rather evenly obtuse (e.g. Scaphimyia). Second costal sector bare ventrally 

 (except in Zenillia grisellina). Mid tibia with one or with more than one ad seta. Hind tibia 

 without pd preapical seta. 



Included genera. Afilomya Robineau-Desvoidy, Cossidophaga Baranov, Neal- 

 somyia Mesnil, Phryxe Robineau-Desvoidy, Pseudalsomyia Mesnil, Pseudoperichaeta 

 Brauer & Bergenstamm, Scaphimyia Mesnil, Xylotachina Brauer & Bergenstamm, 

 Zenillia Robineau-Desvoidy; also some genetically unplaceable species. 



This group is slightly heterogeneous, and to some extent is simply an assemblage 

 of genera that do not fit into any of the other groups here defined. The group 

 cannot be exactly equated to any one of Mesnil's subgroups, but corresponds approxi- 

 mately to his Aplomyiariae and Phryxariae, together with some genera from his 

 other subgroupings. The genus least satisfactorily placed here is, perhaps, Neal- 

 somyia, as this genus to judge from the head facies may be much more nearly related 

 to the C estonia-gr oup or to Buquetia than to the other genera in the Aplomya- 

 Phry xe-group. The relationships of Cossidophaga are uncertain, and it seems 

 possible that this genus is closely allied to the Palaearctic Platymya Robineau- 

 Desvoidy since it runs to the Platymyiariae in Mesnil's (1953a) key to Palaearctic 

 forms. Mesnil has used the number of reclinate orbital setae and the orientation 

 of the apical scutellar setae (whether upwardly directed or horizontal) as differentia- 



