74 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



fore and middle pairs with prominent black bristles on their anterior surfaces 

 near their tips; hairs on the upper portions of the fore coxae delicate, pale. 

 Hind coxa with a single black bristle on its outer surface. Legs pale yellow 

 with black hairs. Tarsi infuscated towards their tips. Fore tarsi scarcely 

 twice as long as the fore tibiae; middle tarsi one and one-third times as long 

 as the middle tibiae ; hind tarsi scarcely as long as the hind tibiae. Hind meta- 

 tarsus distinctly shorter than the succeeding joint. Wings grayish hyaline 

 with a yellowish tinge, broader in the middle, slightly narrowed towards the 

 base. Distal segment of fourth vein moderately bent forward near its middle 

 and ending not very close to the third vein. Distal segment of fifth vein 

 nearly two and one-half times as long as the posterior cross-vein. Halteres 

 and tegulae dark brown, the latter with pale cilia. 



A single specimen taken in sweepings in the pine-woods 

 near Monterey, Calif., July 22, 1896. 



The species differs from the other described North 

 American species in having very little yellow on the 

 abdomen. 



75. Neurigona tenuis {Loew.) 



Plate IV, Fig. 105. 



Saucropus tenuis Loew. 



Loew described this species from a female taken in the 

 Middle States. I have seen two males which I believe 

 belong here — one collected by Mr. C. W. Johnson at 

 Pope's Creek, Md., May 22, 1896, and another some- 

 what larger specimen collected by Mr. A. W. Snow in the 

 Magdalena Mts., N. Mex., during August, 1894. Apart 

 from this difference in size and a few insignificant charac- 

 ters, the two specimens resemble each other very closely. 



Male. Length 3.75-4.25 mm.; length of wing 3-4 mm. Proboscis and 

 palpi yellow, the latter dusted with white. Face very narrow, linear, covered 

 with glistening white dust. Antennae yellow, apex of third joint blunt, pubes- 

 cent and infuscated. Postocular cilia above and below white. Front and 

 thorax dull metallic green, thickly covered with white dust. Humeri in the 

 eastern specimen yellow. Scutellum dull light metallic green, with white dust 

 and yellow posterior border. Abdomen arched, compressed laterally; first 

 segment yellow, slightly infuscated and with the bristles along its posterior 

 edge rather prominent; second and third segments yellow, each with a large 

 black dorsal triangle, fourth segment black edged with yellow. The third 

 and fourth segments have long pale hairs on the venter and there are similar 

 hairs on the posterolateral edges of the fourth and fifth segments. Hypopyg- 

 ium large, hood-shaped, protruding, sessile, black; basal portion opaque and 



