42 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



mesonotal prjescutum with four narrow brown stripes; wings 

 brownish gray, the distal cells with conspicuous macrotrichiae ; 

 abdomen brownish yellow, the lateral margins of the tergites 

 with five dark brown spots ; male hypopygium with the ninth 

 tergite large, deeply notched medially ; caudal margin of the 

 ninth sternite produced caudad into two long, straight append- 

 ages that are tipped with stiff, yellow, spinous bristles. 



Male. — Length, 12 mm.; wing, 12.5 mm. 



Frontal prolongation of the head shiny brownish yellow, darker brown 

 medially; palpi brown. Antennae moderately elongate, if bent backward 

 extending about to the base of the abdomen; scapal segments yellow, 

 basal flagellar segments indistinctly bicolorous, the basal swelling dark 

 brown, the remainder of each segment paler brown ; distal flagellar seg- 

 ments uniformly dark brown. Head dark brown, paler behind, the front 

 and anterior part of the vertex golden-yellow pollinose ; along the inner 

 margin of the eyes more grayish. 



Mesonotum light brownish yellow, shiny, the prsescutum with four nar- 

 row brown stripes ; lobes of the scutum dark. Pleura shiny testaceous 

 yellow. Halteres dark brown, the base of the stem pale yellow. Legs with 

 the coxse shinj' yellow, the base a little infuscated, trochanters yellow; 

 femora yellowish basally, broken before midlength. Wings with a strong 

 brownish gray tinge ; cells C, Sc and the space behind vein Cu yellowish ; 

 stigma dark brown; an obliterative area before the stigma, extending 

 across the inner end of cell 1st M2; veins dark brown; conspicuous macro- 

 trichise in cells R2, Rs, and R5 ; Mi and 2iid Ah except the base, and the tips 

 of cells Mi and Cui. Venation : Rs long, arcuated ; vein R2 persistent ; 

 petiole of cell Mi shorter than m; tn-cu at about one-fourth the length of 

 cell 1st M2, the first section of il/3+4 being shorter than that section of 

 Mi+2. 



Abdomen shiny brownish yellow, the hypopygium darker, especially the 

 base of the ninth sterno-pleurite ; conspicuous dark brown spots near the 

 basal lateral margin of tergites three to six and near midlength of tergite 

 two. Male hypopygium moderately large. Ninth tergite large, the caudal 

 margin with a large, subquadrate median notch, the conspicuous lateral 

 lobes flattened, the ventral surface concave, hollowed out like a spoon, 

 directed caudad ; base of the notch weakly rounded outward, the dorsal 

 surface being impressed at this point. Pleural suture very short, straight ; 

 outer pleural appendage elongate, cylindrical, narrow basally, the distal 

 two-thirds clothed with conspicuous, long, erect, black bristles. Ninth 

 sternite with the caudal margin produced posteriorly into two very con- 

 spicuous straight appendages that lie parallel and close together, the sur- 

 face at the tip and along the proximal face densely set with conspicuous 

 yellow spinous bristles ; the lateral margins with more erect black bristles. 

 Dorsad of the base of these appendages and at the origin of the inner 

 pleural appendages are two conspicuous, pale, fleshy lobes that project 

 strongly laterad. Eighth sternite with the margin weakly trilobed medially, 

 each lateral lobe provided with about two small setae. 



Habitat. — California. 



Holotype, $ (No. 725), Santa Cruz, June 1, 1919 (E. P. 

 Van Duzee). 



