V °1889. n '] PROCEEDINGS OF THE NATIONAL MUSEUM. 439 



BASSUS Fallen. 

 Bassus syrphicola sp. riov. 



Female. — Length, 7 mm . Black, shiuing; head and metathorax densely 

 punctured. A spot on face, clypeus, mandibles, except teeth, palpi, 

 most of the mesopleurae, except the portion just beneath anterior wings, 

 mesosternum, the suture dividing the mesopleurse from the metathorax, 

 inetapleuraB and legs, ferruginous ; the apex of posterior tibiae and their 

 tarsi, black; lateral margins of mesothorax, tegulae, a spot in front 

 and beneath it, a central line on scutellum and a transverse line on 

 postscutellum, white. Metathorax without keels. Abdomen slightly 

 compressed at apex, the three basal segments sculptured, the following 

 segments almost smooth, shining, but showing a flue reticulate punc- 

 tuation; all the segments are narrowly edged at apex with white and 

 from the third the white color is obliquely dilated at the sides. Wings 

 hyaline, iridescent ; stigma and veins brown-black, the stigma with a 

 pale spot at base ; areolet wanting. 



Male. — Length, 6 mm . Agrees with the female except the face wholly 

 and the anterior orbits to summit, the antennae beneath, clypeus, man- 

 dibles, palpi and the whole under surface of the thorax, except a black 

 spot beneath wings, and lateral hook-shaped marks on mesonotum, are 

 wholly white or yellowish-white. 



Habitat.— San Francisco, Cal. 



Described from one male and two females received from Mrs. L. A. 

 Burkholder, reared April 29, 1881, from a puparium of a Syrphus-fly 

 found on rose. 



Bassus orbitalis sp. nov. 



Female. — Length', 5.4 mm . Black, shining, punctate. Anterior orbits, 

 lower part of cheeks, clypeus, mandibles, palpi, prosternum, a hook- 

 shaped mark on mesosternum, anterior and middle coxa* and trochan- 

 ters, a broad band on posterior tibhe, lateral margins on mesothorax, 

 teguiae, a spot in front ami beneath it, a spot at insertion of posterior 

 wings and extending along the ridge separating the mesothorax from 

 the metathorax, two short lines on disk of mesonotum, a broad medial 

 line on scutellum, and the postscutellum, white. Metathorax with a 

 transverse keel on the upper margin of posterior face and with trian- 

 gular areas laterally. Legs ferruginous ; the posterior tibiae, except 

 the broad white baud at the middle, and their tarsi, black. Abdomen 

 compressed at tips, rugulose, the apices of middle segments and the 

 two or three termiual segments, smooth ; the first segment is bicari- 

 nated at basal half, and the apex in the middle exhibits a small white 

 stain or line. Wings hyaline ; stigma and veins brown ; the stigma at 

 base and the costa3 basally are pale. 



