ABT. 17. NORTH AMERICAN PHOROCERA ALDRICH AND WEBBER. 3 



3. (Subgenera of Phorocera) Inner forceps of male united into a broad, long 



organ, whicb is suddenly constricted into a short beak at tip ; female with 

 fifth sternite developed into stout plates, between which lies a very mi- 

 nute piercer Subgenus Phorocera Kobineau-Desvoidy. 



Inner forceps of male united into a slender beak or hook ; female without 

 large sternal plates and piercer, distinguished by elongated abdominal seg- 

 ments or by an appendage or distinct fold at bend of fourth vein {Euphoro- 

 cera, Neophorocera, Euphoroceropsis) . 



Subgenus Parasetigena Brauer and Bergenstamm. 



Inner forceps of male separated as usual ; female not with large sternal 

 plates, elongated abdomen, or appendage at bend of fourth vein 4 



4. Abdomen in both sexes very wide and deep, almost globose ; unless contracted 



in drying the fourth segment closing in a slit above the genital opening. 



Subgenus Patelloa Townsend. 

 Abdomen in both sexes of ordinary form Subgenus Neopales Coquillett. 



5. Front with an extra row of bristles, 3 to 6 in number, outside the usual row 



on each side Madremyia Townsend. 



Front without additional bristles, face less receding than usual. 



Murdockiana Townsend. 



6. Second antennal joint nearly as long as third Nemorilla Rondani. 



Second antennal joint much shorter than third (Zenillia Robineau- 



Desvoidy) 7 



7. (Subgenera of Zenillia.) Abdomen in both sexes very wide and deep, almost 



globose; fourth segment unless contracted in drying clos»ing in a slit above 



genital opening Subgenus Eusisyropa Townsend. 



Abdomen of ordinary form 8 



S. Discal macrochaetae usually absent, when present never arranged in pairs; 

 abdominal hairs always erect, often approaching macrochaetae in size; 



cheeks narrow Subgenus Parexorista Brauer and Bergenstamm. 



Discal macrochaetae present or absent, but if present always arranged 



in pairs ; abdominal hairs usually depressed 9 



9. Penultimate joint of arista usually elongate, discal macrochaetae always 

 present ; black subshining species with black palpi. 



Subgenus Phryxe Robineau-Desvoidy. 



Penultimate joint of arista always short; discal macrochaetae present or 



absent Subgenus Zenillia Robineau-Desvoidy. 



LIST OF SPECIES. 



Genus Nemorilla Rondani. Genus Zcnillm Robineau-Desvoidy — 



maculosa Meigen (pyste Continued. 



Walker). Subgenus ZeniUia — Continued. 



parva Coquillett. coquilletU, new species. 



insolens, new species. lobeliae Coquillett. 



Genus Zenillia Robineau-Desvoidy. valens, new species. 



Subgenus Zenillia. eudryae Townsend. 



amplexa Coquillett. coerulea, new species. 



nrotuherans, new species. 



' . „ •,, i-i formosa, new species. 



helvma Coquillett. . , . 



ochracea Van der Wulp. inflaUpalm, new species. 



marginata, new species. PoUta Coquillett. 



angustivitta, new species. setinervis Coquillett. 



