OSTEX SACKEX ON WESTERN DIPTERA. 207 



tip; tarsi brown, except the base, ^N^hich is paler. Halteres brovp-uish. 

 Wings with a distinct pale brown tinge, somewhat yellowish along the 

 costa; nearly obsolete clouds, visible with the magnifying-glass only, on 

 the central cross- veins and on the bifurcation of the third vein ; veuatiou 

 like P. riifocincta. Length, Il-IB"^-". 



Hab. — Tosemite Valley, Cal., June 5 ; Georgetown, Colo. (8,500 feet 

 altitude), August 13. A male and two females. Seems to resemble the 

 European P. scutellaris. 



P. mefallica Walker from Albany Elver, Hudson's Bay, may be this 

 species ; but Walker states that the venation differs from that of the 

 other Ptyclwpterce, although it does not appear from his explanation in 

 what the difference consists. 



BiTTACOMOEPHA CLAVIPES (Fabr.). — A specimen from Oregon in Mr. 

 H. Edwards's collection in San Francisco ; other specimens were col- 

 lected in Clear Creek Caiion, Colorado, by Mr. J. D. Putnam, of Daven- 

 port, Iowa; near Boulder City, Colorado, by A. S. Packard, June 29.* 



Genus Protoplasta. 



In my Monograph of the ISTorth American Tipnlid^e (Monographs of 

 North American Diptera, vol. iv, p. 309), I established two groups of 

 the section Ptycliopterina, the second of which contains three remarkable 

 and closely allied genera, — Protoplasa (better Protoplasta), from the East 

 ern United States; Taiiyderus, from Chili', and Macrochile, a fossil form 

 found in the Prussian amber ; all of which with but a single species. 

 These three genera and species differ from the PtycJiopterina of the first 

 group {PtycJioptera and Bittacomorpha) in thefoUowing characters : — A 

 subcostal cross-vein is present; the second submarginal cell is much 

 longer than the first ; the number of posterior cells is raised to six, in 

 consequence of the presence of a supernumerary longitudinal vein in the 

 first posterior cell ; collare large. 



I have discovered a fourth species in California, which possesses the 

 general characters of the PtycJiopterina, as well as the particular char- 

 acters of this second group. The characters enumerated below are 

 merely those in which P. vipio differs from the generic characters of 

 Protoplasta as given 1. c.,p. 316, In judging of their importance, it must 

 be borne in mind that the original specimens of P. fitclii, at the time 

 when I described them, were old specimens, while I made the descrip- 

 tion of my new species before the specimen had dried. Some of the 

 minor differences may be due to this circumstance. 



Eyes finely pubescent; proboscis together with its large fleshy 

 lips a little longer than the head; antennse 15-jointed, first joint but 

 little longer than the second ; joints of the flagellum elongated, very 

 slightly incrassated on their anterior half, with verticils on the incrassa- 



* I discover a slip of the pen in my description of this species : Monographs, iv, p. 

 31G, line 2 from top, for hroicn, read uhite. 



