OSTEN SACKEN ON WESTERN DIPTERA. 321 



County, in July. The males of most species are provided with very 

 remarkable appendages on the hind legs. 



Ehamphomyia is represented in my collection by more than a dozen 

 species, taken in the same localities. 



Of the group Tachydromina, I have two or three species, belonging to 

 the genera Platypalpas (TachydromiaMeig.) and Tachypeza. 



The only species hitherto described are : — 



Empis barbata Loew, Gentur., ii, 19. — California. 



Ehamphomyia ltjctuosa Loew, Centur., vol. ii, 290 (syn. R. lugens 

 Loew, Ceutur., ii, 30). — California. 



Family LONCHOPTERID.E. 

 Lonchoptera sp. — San Rafael, May 29. 



Family PLATYPEZID^. 

 Platypeza sp. — Santa Barbara, Cal., January 29. 

 Family SYEPHID^E. 



As I left San Francisco, going east, about the middle of July — that 

 is, before the best season for collecting SyrpMdce, which is August and 

 September, had really begun — my collections cannot be expected fairly 

 to represent the fauna. 



The species of Paragus (1 species), Plpiza (1 sp.), Orthoneura (1 sp.), 

 Chilosia (3 sp.), which I found, have a remarkable family resemblance to 

 the species from the Atlantic States and to the European ones; some of 

 them will probably prove to be identical. The same may be said of 

 Melanostoma (3 sp.), Syrphus (6 sp.), Mesograpta (2 sp.), Splicer ophoria (3 

 or 4 sp.), AUograpta (1 sp.), Baccha (2 sp.). 



In the genus Syrphus, the common occurrence of the European S.py- 

 rastri in California, Utah, and as far east as Colorado, is remarkable 

 when we recollect that it has never been found east of the Mississippi. 

 Macqu irt received it from Chili. The question how it got to these re- 

 gions is an interesting problem. 



The other species of SyrpJius are either identical with eastern species 

 or closely allied to them. Both Mesograptce are species also occurring in 

 the Atlantic States. The Sphceropliorice seem to be more numerously 

 represented in California than east of the Mississippi. 



Peculiarly western is the new genus Uupeodes, with a single species 

 of common occurrence from California to Colorado. 



Of Eristalis I have three species from California, two of which reach 

 eastward to Colorado. 



Relopliilus is represented by two species, one of which (H. latifrons 

 Lw.), common in the environs of San Francisco, has a wide easterly 

 range, to Nebraska and probably beyond. The other (H. polygrammus) 

 is a very peculiar form, and occurs high up in the Sierra Nevada and in 

 Oregon. 



