172 g DIPTERA OF NORTH AMERICA. 



3. S. Obsoleta Loew. 9 . (Translated fromBerl. Entom. Zeitschr. 1861, 

 p. 358, by R. Osten-Sacken.) — Opaca, capite toto, scutello pleurisque ex 

 flavo, pectore et abdomine ex cano cinereis, antennis pedibusque nigris ; 

 alae hyalinae, dilute cinerascentes, guttis limpidioribus quinque obsoletis- 

 simis. 



Opaque, the whole bead, scutellum and pleurae yellowish-cinereous, pectus 

 and abdomen hoary-cinereous, antennae and feet black ; wings hyaline, 

 with a pale cinereous tinge ; five almost obsolete clear spots. Long, 

 corp. 0.07. Long. al. 0.09. 



Head altogether yellowish-cinereous, antennae black, face very 

 vaulted,* peristoma ciliated with moderate hairs. Thorax conco- 

 lorous with the head, pectus subglaucous. Scutellum yellowish- 

 cinereous. Abdomen hoary-cinereous, subglaucous, opaque. Legs 

 altogether black, slightly pollinose with white. Halteres impure 

 yellow, stem brown. Wings hyaline, tinged with very pale cine- 

 reous, marked with five clear very obsolete spots ; transverse veins 

 not infuscated ; second costal segment more than thrice longer 

 than the third. 



Hab. Washington. (Osten-Sacken.) 



* The original has fornicatus, which means forming a rounded arch with 

 an empty space below. — 0. S. 



