190 CALIFORNIA ACADEMY OF SCIENCES. [Proc 3D Ser. 



part of the eyes is red-brown, while the lower part is blackish; antennae 

 about twice as long as head, composed of fourteen segments; forelegs of 

 female much shorter than middle and hind legs; not so in male; in both 

 sexes middle legs nearly as long as hind legs; hind tibiae with a pair of small 

 spurs, fore and middle tibiae without spurs; wings (PI. XIX, fig. 3) with 

 venation as in Blepharocera fasciata (Europe) and capitata (northeastern 

 North America), that is, with M^ incomplete (incomplete vein in the hind 

 margin), no cross- vein between media and cubitus (no cross-vein between 

 veins four and five), and R^ wholly fused with R^ (second vein simple, 

 without branch); body not hairy, and pale fuscous in color without special 

 markings. 



Length, male 10 mm.; female 11-12 mm. 



One free-flying adult male, San Francisquita Creek, near 

 Stanford University, May 19, 190T ; and numerous males 

 and females dissected out from pupal cases, the specimens 

 being fully developed and ready to issue ; taken in April, 

 May, and June, 1900 and 1901, from Corte de Madera, San 

 Francisquita, Los Trancos, Steven's, Campbell's and Los 

 Gatos creeks, all in the Sierra Morena and Santa Cruz 

 mountains, within twenty miles of Stanford University, 

 California; and in Smith's Creek (Mount Hamilton) and 

 Coyote Creek (near Gilroy Hot Springs) in the Coast 

 Range, at thirty-five and sixty miles respectively from 

 Stanford University, California. 



This distribution is practically the same as that so far 

 determined for the species Bibiocephala comstocki and 

 Bibiocephala doanei. Named for Dr. David Starr Jordan. 



Immature Stages. The larvae (PI. XX, figs, i and 2) are, when full grown, 

 7 mm. to 9 mm. long; the lateral processes are short and inconspicuous; 

 there are no strong markings, the whole body being mostly pale and com- 

 paratively soft (z. e., not strongly chitinized ) ; the dorsal surface of each 

 segment bears traces of an incomplete quadrangular, blackish patch; the 

 markings of the head consist of a median patch bearing a central triangle 

 and two diagonal lines on each side of it, and a pair of lateral patches. 



The pupa measures from 5.5 mm. to 6.5 mm. in length, is black, and is 

 characterized by having its dorsal prothoracic respiratory plates markedly 

 curving inward, so that the tips nearly or quite meet, the inner margin of the 

 plates being thus strongly concave. The plates themselves are rather broad 

 (as contrasted with the similarly inward curving but narrow plates of 

 Bibiocephala doanei). 



Both larvae and pupae of B. jordani are found commonly 

 associated with the larvae and pupae of Bibiocephala comstocki 

 and B. doanei. 



