OSTEN SACKEN ON WESTERN DIITERA. 277 



bescence, visible in a certain light only; feet straw-yellow ; tarsi brown- 

 ish toward the tip; wings grayish-subhyaline ; costal cells brownish- 

 yellow; costal and first longitudinal veins black on their proximal half, 

 brownish-yellow toward the end ; tegulre whitish, their margins yellow- 

 ish; knob of halteres yellow. The proboscis of the male does not reach 

 the end of the abdomen; that of the female does not reach beyond it. 

 Length 9-ll mm . 



Rab.— Webber Lake, Sierra County, California, July 23-26, not rare, 

 flying in circles around flowers. Three males and two females. A male 

 and a female from Calaveras, Sierra Nevada, California, June (G-. E. 

 Crotch), have the proboscis a little longer than the abdomen. 



This species is easily distinguished from E. smaragdinus 9 by its 

 smaller size, blue color, shorter proboscis, less yellowish wings ; the 

 two latter characters also distinguish the males, which are somewhat 

 alike in coloring. 



All my specimens, as far as I remember, were more uniformly blue 

 when I took them, and seem to have assumed the purple and even 

 greenish tinges, which they have now, in the process of drying. 



3. Eulonchus tristis Loew, Centur., x, 19. — I found a male and a 

 female in the Coast Range, in the woods of Sequoia sempervirens, above 

 Santa Cruz, Cal., on a flower, May 21, 1876. 



4. Eulonchus marginatus n. sp. — Metallic green, with bluish re- 

 flections on the scutellum, the anterior margins of the segments, etc.; 

 venter metallic blue. Antennae black. Thorax clothed with dense 

 pale yellowish-white erect pile; abdomen with a short appressed pu- 

 bescence, which forms whitish cross-bands along the hind margins of 

 the segments. Legs black, and only the knees yellowish-white. Tegulse 

 with very distinct black margins. Wings subhyaline ; all the veins 

 dark brown, except the distal end of the costa and of the first posterior 

 vein, which are reddish-yellow. Proboscis a little longer than the ab- 

 domen. Length 9 mm . 



Hab. — Napa County, California (H. Edwards). A single specimen, ap- 

 parently a male. The petiole of second submarginal cell is subobsolete ; 

 as I have only one specimen, I cannot say whether this is a permanent 

 character of the species. 



Pterodontia misella n. sp. — Black; clothed with black pile; 

 scutellum black, obscurely reddish on its latter half; second abdominal 

 segment (that is, the first visible segment ; the true first segment is 

 concealed under the scutellum) black, with an obscurely marked reddish 

 spot on each side a little back of the scutellum ; segments 3-6 rufous, 

 the third and fourth with square black spots in the middle, that on the 

 fourth being narrower; they are confluent with each other and with the 

 black of the second segment. Yenter rufous ; hind margins of segments 

 2-5 black. Tegulse brownish, with broad dark brown margins. Legs 

 brownish-yellow, the four posterior femora black; ungues reddish at 

 base, black at tip. W T ings subhyaline ; veins yellow ; venation similar 



