6l4 CALIFORNIA ACADEMY OF SCIENCES. 



inal segment a little widened laterall}^; that of third seg- 

 ment but slightly wider and of quite equal width through- 

 out with a pointed projection on median line on anterior 

 edge. Fourth segment blue-black only on posterior half, 

 the anterior portion widely yellowish like other light por- 

 tions of abdomen, onl}^ a narrow median line running for- 

 ward from black but not reaching base of segment. Ab- 

 domen with white pile, except on black hind margins of 

 second and third segments and a narrow space of the 

 yellow in front of them, on which is black pile. Venter 

 light yellowish black apically. Bases of all the tibi^ red- 

 dish yellow. Wings clear glassy hyaline, with rich brown 

 clouds on small cross- vein, basal portion of third vein, 

 second vein beyond the origin of third to opposite stigma, 

 stigma and auxiliary and first veins opposite, and cross- 

 veins at distal end of second basal cell. 

 A very elegant species. 



39. VoLUCELLA HAAGii Jacnn. El Taste, Baja Cal- 

 ifornia (Eisen). September. Two males. One speci- 

 men seems to have the eyes contiguous for a somewhat 

 o-reater extent than the other. 



40. VoLUCELLA isABELLiNA Willist. Tucson, Ariz. 

 One male. Dr. Williston describes only the female in 

 his monograph (p. 140). The present male specimen 

 measures only 13^ mm. in length. The honey-yellow 

 stripe on each side of thorax between humerus and scu- 

 tellum is faint. The scutellum is blackish at base. The 

 thorax has seven narrow black vittai, counting one on 

 each side on outer edge of the faint honey-yellow stripe, 

 the three outer vittas on each side converging posteriorly, 

 and the middle vitta ending posteriorly in a transverse 

 dark line bordering the yellowish prescutellar parallelo- 

 gram. The first abdominal segment is yellowish, except 



