June, 1912.] Aldrich : Two Western Species of Ephydra. 101 



Abdomen sub-shining metallic blue, fifth segment nearly a half longer 

 than the fourth, hypopygium very small and retracted. 



Legs opaque greenish-black, knees hardly yellowish, tarsi strongly con- 

 trasting deep yellow, only the tip of the last joint a little infuscated; claws 

 black, long and straight. 



Wings of ordinary appearance, veins rather pure yellow near base. 



Length 3.6 mm. ; of wing 3.5 mm. 



A single made, Garfield, Utah, July 9, 191 1. The specimen was 

 not recognized as different from subopaca until after the work of the 

 day was finished, and I am unable to state just where I got it. I 

 collected along brackish water from Smelter station west and north 

 to the shore of Great Salt Lake, and captured the specimen in that 

 small region. 



The species has so many good marks of distinction that it will be 

 recognized without difficulty. 



Ephydra viridis Hine. 



Cccnia virida Hine, Ohio Naturalist, IV, 65. 



A large, robust, dull-green species with yellow knees, a deep depression 

 in the front just anterior to the oceller triangle, and ornamented hind tarsi in 

 the male. 



Male. — Front shining dark green except the wide orbits and the ocellar 

 triangle, which are seal-brown pollinose ; a deep depression just in front of 

 the foremost ocellus ; a few minute hairs on the shining portion of the front, 

 and on the lower corners one pair of bristles, curved toward each other ; 

 the frontal orbits bear two pairs of f. o. bristles bending outward over the 

 eyes, and a few hairs extending down to the face. Antennae black, third 

 joint large, arista with distinct, short plumosity. Face moderately promi- 

 nent, convex in profile, covered with brown pollen ; the antennae are wide 

 apart, and the space below them is only a little less pollinose ; hairs of face 

 coarse, with a row of little bristles across above and another along the oral 

 opening. Sides of face, cheeks and back of head with brown pollen ; below 

 the eye a bare space extends to the mouth, and behind this is a large bristle 

 on the edge of the mouth, behind which the beard begins. 



Thorax dark shining green, with a little thin brown pollen ; hairs rather 

 small, bristles strong, chsetotaxy normal except that there is no post-humeral 

 (interhumeral) ; pleurae with a little more pollen, which becomes olivaceous 

 on the sternopleura ; one large bristle and a few small ones on the posterior 

 edge of mesopleura ; calypter moderately large, yellow and with brownish 

 yellow hairs ; halteres yellow. 



Abdomen green, sub-shining, fifth segment nearly a half longer than 

 fourth, hypopygium very small and inconspicuous. 



Femora and tibiae all sub-shining greenish-black, the knees decidedly 

 yellow, trochanters sometimes a little yellow ; front and middle tarsi of plain 



