APPENDIX. 



MIXOGASTER. 



Mixogaster Macquart, Dipt. Exot., ii, 2, 14, 184'2. 



This genus will be recognized without difficulty from what has been 

 given in the introduction. The known species resemble Ceria in shape, 

 but with the head of Microdon. Type of genus, M. conopsoides Macquart, 

 South America. Thomson has described a species from. Australia. 



Mixogaster mexicanus Macquart, Dipt. Exot., ler Suppl., 123, pi. x, fig. 15.— 

 Mexico. 



PIPIZA. 

 Pipiza crassipes. 



Pipiza crassipes Bigot, Ann. Soc. Ent. Fr., 1884, 557. 



Habitat. — North America (Bigot). 



9 . Length, 7™"^. Nigra, vix nitida. Antennarum segmento tertio 

 chetoque fulvis ; facie cinereo pared tomentosd; calyptris albis, Jialterihus 

 testaceifi; alis pallidissime fuscanis, basi hyalinis, macula stigmaticali 

 testaced; pedibus posticis parum incrassatis. 



D'un noir peu luisant, presque glabre. Antennes 3e segment et 

 chete fauves; face avec un fin duvet grisatre, clair seme; un peu de 

 duvet blanc sur les flancs ainsi que sur les cuisses; cuillerons blancs, 

 balanciers testac^s; ailes un peu roussatres, hyalines a la base, macule 

 stigmatique roussatre; genoux fauves, pieds posterieurs leg^rement 

 epaissis, surtout le m^tatarse. — 1 specim., — , Bigot, I. c. 



Pipiza puelchella, ante, p. 27. 



It is not improbable that Ghrysogaster Apisaon Walker, List, etc., iii, 

 572 (New York), is the same as this. At least the hairy eyes and elon- 

 gate antennae indicate that it is a Pipiza (Pipizella) or Psilota. 



PSIIiOTA. 



Psilota buccata. 



An examination of a number of specimens in the National Museum 

 enables me to give a more complete description of this species. 



$ . Length, 8™"". Metallic black. Antennae black; third joint elon- 

 gate, about four times as long as wide, reaching nearly to the epistoma. 

 Epistoraa small, not much projecting. Face white pilose. Eyes long, 

 luteous yellow pilose. Dorsum of thorax rather thickly reddish yellow- 

 ish pilose. Abdomen elongate oval, shining black with a light brassy 

 reflection; pile reddish yellowish, abundant, erect. Legs black. Base 



291 



