SYNOPSIS OF NORTH AMERICAN SYRPHID^. 51 



and with black pile. An tennsB reddish yellow, the third joint at the outer 

 end blackish. Thorax and scatell urn bright metallic green. Abdomen 

 narrow, elongate, attaining its greatest width at the end of the fourth 

 segment ; first segment, and the front part and sides of the second, bronze 

 green, not much shining; second segment in the middle with two small 

 oval yellow spots, behind subopaque black ; third, with two elongate 

 yellow spots, reaching from the front margin to beyond the middle of the 

 segment, and touching the lateral margins in front; fourth segment 

 similar, but the spots a little less elongate, and the posterior part and 

 lateral margins of the segment shining green ; the nearly-concealed fifth 

 segment and the hypopygium shining green black. Legs sometimes 

 wholly yellow, except a brownish ring on the front tibiae; usually the 

 front and middle femora and tibite with broad brown rings, and the hind 

 femora and tibiae with broad black rings ; the front tarsi lightly, the hind 

 tarsi except the tip of the first joint, darker, brownish; hind metatarsi 

 scarcely at all thickened. Wings tinged with brownish, the stigma 

 yellow. 

 Five specimens, Washington Territory (H. K. Morrison). 



Melauostoma trichopus. 



S;irphus trichopus Thomson, Eugenies resa, etc., 502. 



Rahitat. — California (Thomson). Niger, facie, abdominis maculis late- 

 ralibus scntelloque plumbeis, tibiis tarsisque anterioribus dilute fuscis. 

 S . Long. 8-9 mill. Patria, California. 



kS. fenestrato Macq. simillimus, thorace baud viridi, costa in apice 

 ipso excurrente distinctus. Caput hemisphsericum, inferue breviter 

 rostt ato-productum, infra antennas vix impressum, tuberculo supra 

 clypeum parvo; occipite opaco seneo-nigro; oculis froute late cohaireu- 

 tibus, interne ad os baud descendentibus, margine potr ico vix siuuato, 

 albido-pruinoso; fronte supra antennas dense nigro-pilosa; epistomate 

 nitido, seneo, lateribus parcius albido-pubescenti, apertura oris oblonga, 

 antice constricta; geuis linea obliqua impressa ab epistomate discretis; 

 gula i)lumbea, pallido-pilosa. Antennae basi paullo distantes, divari- 

 catse, subdeflexse, nigrae, articulo 3:o elliptico brunneo, seta basi nigri- 

 cante. Thorax plumbeo niger, subopacus, fuscopilosus; scutellura 

 plumbeo-vireseens, longius nigro-pilosum. Alae abdomine longiores, 

 griseo-hyalinae, cellula post-costali obscure flava; costa in ipso apice 

 al» desiuente, cellula discoidali nervum transversum ordiuarium in 

 quarta sua anteriore parte excipiente, nervo exteriore baud flexuoso et 

 terminal! apice extus appendiculo parvo instructis, hoc nervo exteriore 

 basi inferno flexuoso; nervo spurio ante apicem cellube discoidalis ab- 

 rupto, brachii abscissa 4 : o ta nervo transverso breviore. Halteres nigri. 

 Abdomen thorace cMmidio longius, apicem versus angustatum, sat dense 

 et longe praesertim basi fusco-pilosum, atroholosericeum, segmentis 5 :o 

 brevissimo et 6:o totis, 2-4 maculis lateralibus prope basin plumbeo- 

 schistaceis, his fascias sensim minus late interruptas formantibus. 

 Pedes nigri, femoribus omnibus tibiisque posterioribus sate longe pilosis. 



