FAM. BLEPHAROCERID.î: i3 



8. Genus BIBIOCEPHALA, Osten-Sacken 



Bibiocephala. Osten-Sacken, Gaol. Survey of the Terr, for 1873, p. 564 (1874); Loew, Schles. Zeitschr. 



f. Ent. N. F. Vol. 6, p. gS (1877I; Osten-Sacken, Berl. Ent. Zeit. Vol. 36, p. 409 (1892) 



Vol. 40, p. 161 (i8g5); Kertész, Cat. Dipt. Vol. i, p. 281 (1902); Kellogg, Proc. Calif. Acad. Sc. 



(3) Zool. Vol. 3, pp. 187-221, pi. 18-22 (1903) (revision of the genus); Aldrich, Cat. N. Amer. 



Dipt., p. 171 (190 5) {grandis). 

 Agathon. Röder, Wien. Ent. Zeit. Vol. g, p. 23o (1890) [eleganhila) . 



Characters. — An incomplete vein near the posterior margin of the wings; second longitudinal 

 vein with two branches; cross vein connecting veins four and five; anterior branch of second vein, and 

 veins two and three all separating at a common point or close together. 



Biology. — Males and females and pupœ known. On June 22 to 25 (1901) Kellogg found 

 imagines oi B. elegaiitula numerous among the boulders of Big Thompson stream. Estes Park, Colo- 

 rado (altitude 7,5oo feet), where the stream breaks through the Willow Park terminal moraine. At this 

 time, old pupae and empty pupal skins were found, but no larvae except two very young ones. On 

 August 10 to 12, the flies were found still common and numerous larvae, )'oung and old, but no pupae. 

 In three other nearby mountain torrents, viz. Wind Creek, Mill Creek and vSouth Fork of Big Thompson, 

 adults and old pupae were found. A note made at this time is as follows : k It seems to me that I have 

 got here just as the last adults of one generation are issuing, and that the larvae of August are larvae 

 from eggs laid by these adults. This would mean a generation of flies appearing about July i, sa}", and 

 a second one appearing later, say about September i5. » This is, of course, mere conjecture. 



The larvae of B. doanei were taken as early as February 25 (Los Trancos Creek, California), and 

 as late as July 26 (Red Cap Creek, Hoopa Indian Reservation, Humboldt County, California), and in 

 all the intervening months; pupa? are first recorded March 3i (Campbell Creek, California) and from 

 then till July 26 (Red Cap Creek, Humboldt County, California); the onl}- free-flying imago was taken 

 on July i5 (Congress Springs, Campbell Creek, California). 



Kellogg's earliest recorded date of taking the laryae of B. comstocki is February 11 (Alembique 

 Creek, California), the latest April 3o (Stevens Creek, California); the earliest pupae are of the date 

 February 27 (Los Gatos Creek. California). A free-flying imago was taken April 6 (Saratoga Springs, 

 Campell Creek, California). 



Geographical distribution of species. — The four species included in this genus are all 

 North American coming trom the Rocky, Sierra Nevada and Coast Range mountams of Colorado, New 

 Mexico and California. 



1. B. grandis, Osten-Sacken, Geol. Survey of the Terr, for 1873, p. 566, fig. (1874) (Colorado, New 



Mexico, Utah, Idaho). 



2. B. comstocki, Kellogg, Calif. Acad. Sc. (3), Vol. 3, p. 192, pi. 18, f. 6 and 7, pi. 20, f. 5 and 6, pi. 21, 



f. 4 (1903) (California). — PI. I, Fig. I , 2, 5, 6, II , 



3. B. doanei, Kellogg, Psyche, Vol. 9, p. 39 (1900) (Liponeiira) (California). — PI. I , Fig. 10, 13; 



PI. 2, Fig. 23. 



4. B. elegantnla, Röder, Wien. Ent. Zeit. Vol. 9, p. 23o (1890) {Agathon) (Sierra Nevada Mountains, 



Idaho, Colorado). — PI. 2, Fig. 14, 15, 19. 



