OSTEN SACKEN ON WESTERN DIPTERA. 243 



{aaa) Basal portion of the wiug more or less dark; no black spots 

 at the proximal end of the second submargiual, sec- 

 ond and third posterior cells : 

 hastardi Macq., D. E., ii, 1, p. 60. — North America. 

 2^au2)er Loew, Centur., viii, 48. — Illinois. 

 *fur n. sp. — Texas. 

 IV. Group in which the costal cell is checkered, hyaline, and black : 



*(jediims Fab., Wied., i, p. 202 (syn. irrorata Say and 

 Macq.). 

 Schiner (Fauna Austr., Dipt., i, 52) says that the larvse of Argyra- 

 moeba live parasitically in,, pupae of Lepidoptera. That this is far from 

 being universally the case is proved by the fact that A. ceplms and A. 

 fur were bred from the nest of a Mud-wasp in Texas, forming tubes of 

 clay five or six inches long, pasted together like organ-pipes. The nests 

 were found near Dallas, Tex., by Mr. Boll, and are now in the Museum 

 of Comparative Zoology in Cambridge, Mass. The pupas bored their 

 way directly through the clay, and the exuviae remained in the hole. 

 The Hymenopteron which builds these nests is very probably a Pelo- 

 pcBus ; the larva of the fly probably devours the larvfe of the wasp. 



I observed A. cedipus in the Sierra Nevada persistently flying round 



a hole in a pine log, probably containing the nest of some Hymenopteron. 



Argyrmiueba leucogaster Meig. was bred from the nest of a Cemonus, 



living in deformed reeds. The article of Mr. Frauenfeld on the subject 



is well worth reading (Verh. zool.-bot. Gesellsch., 1864, 688). 



A. suhnotata Meig. was bred by the same author from a nest of 

 Chalicodoma muraria Lin. (Verh. zool.-bot. Ges., 1861, 173). 



A. sinuata was bred by Mr. Laboulbene from the nest of a Hymenop- 

 teron, probably Megaohile muraria (see Ann. de la Soc. Eutom. de 

 France, J 857, 781). 



1. Argyramceba cedipus Wied. (syn. irrorata Say, Macq.). — Seems 

 to have a very wide distribution all over North America, even quite far 

 in the northwest of the British possessions ; according to Schiner, also 

 in South America. I brought a couple of specimens from Webber Lake, 

 Sierra County, 'California. A specimen from the Shasta district was 

 given to me hj Mr. H. Edwards. A specimen which I took in Sonoma 

 County, July 4, is larger, and the black dots in the latter part of the 

 wiug are much more scarce. 



2. Argyramceba limatulus Say. — I retain under this name a group 

 of specimens from the Geysers, Sonoma County, California (May 5-7) ; 

 Fort Bridger, Wyoming (August 7) ; Fair Play, Colorado ; Spanish 

 Peaks, Colorado ; Sangre de Cristo Mountains, New Mexico (the latter 

 collected by Lieut. W. L. Carpenter). The extent of the black on the 

 wings in these specimens is very variable, even in those taken on the 

 same day and in one locality ; in many, there is very little black left 

 except the dark clouds on the cross- veins. Whether these specimens 

 really belong to the A. limatulus I am not prepared to affirm. Say's orig 



