OSTEN SACKEN ON WESTERN DIPTEEA. 285 



cies, from Texas, also occur abundantly in the countries adjacent to. 

 the Mediterranean, the Black, and the Caspian Seas, and extend into 

 Central Asia. 



Mieroslylum, with two or three species in Texas and Kansas, is very 

 abundantly represented in Southern Africa, and occurs also in the East 

 Indies and Australia. 



Laphria. 



1. Laphria (Dastllis) astur n. sp., $9. — Like Laphria posticata 

 Say, but the tibiae beset with yellow pile. Length 14-20""". 



Black; face, occiput, thoracic dorsum, and the two penultimate ab- 

 dominal segments densely clothed with yellow hairs; palpi with black 

 pile; a tuft of black bristles above the mouth is usually concealed 

 under the overhanging yellow hairs of the face ; scutellum with black 

 pile. Legs black; front femora on their hind side and all the tibise 

 with long yellow hairs; on the hind tibite, the yellow hairs do not quite 

 reach the tip. Proximal half of the wings subhyaline; distal half more 

 or less brownish, the inside of the cells being paler. 



Hah. — Common in California; Petaluma, April 27; Mendocino, April 

 29 (J. Behrens) ; Saucelito, May 16. Most of my specimens, however, I 

 caught about Webber Lake, Sierra Nevada (July 23-25). I have six 

 males and nine females. 



This species varies in the extent of the yellow pile, especially around 

 the neck, on the pleuras, and on the legs. As a rule, specimens taken at 

 high altitudes have more yellow pile than those taken at lower ones. A 

 specimen taken at Petaluma, therefore, but little above sea level, had 

 no trace of yellow hairs on the tibioe. The specimens from Webber Lake 

 had a great many yellow hairs. The fan- like row of hair in front of 

 the halteres is, in different specimens, either yellow or black. Some 

 specimens have a yellow tuft in front of the wings, and another in front 

 of the coxse ; in others, they are wanting. On the tibise, the yellow 

 hairs appear sometimes only at the base. 



2. Laphria (Dasyllis) columbica Walker, The Naturalist in Van- 

 couver's Island and British Columbia, by J. K. Lord, London, 1860^ 

 338. 



" Male. — Black, with a very slight bronzy tinge ; head very thickly 

 clothed with slightly gilded hairs; vertex and hind side with black hairs ; 

 mystax composed of black bristles. Thorax clothed with short black 

 hairs; fore part with a fawn-colored pubescence; a band of slightly 

 gilded hairs across the hind part of the scutum. Abdomen clothed 

 towards the tip with slightly gilded hairs ; legs mostly clothed with 

 slightly gilded hairs, except towards the tips; hind femora incrassated, 

 with black hairs; hind tibiae livid, and with slightly gilded hairs, ex- 

 cept towards the tips. Wings blackish, discs of most of the areolets 

 cinereous; veins and halteres black. Length of the body 9 lines; af 

 the winffs 16 1. 



