ZooL.— Vol. III.] KELLOGG- NET-WINGED MIDGES. 191 



2. Blepharocera osten-sackeni, sp. nov. 



Plate XVIII, Fig. 2; Plate XIX, Fig. 2; Plate XX, Figs. 3 and 4. 



Eyes of female contiguous, and bisected by an unfacetted stripe; eyes of 

 male separated by a considerable space, and bisected by a line, the upper or 

 large-facetted portion including a much larger part of the eye in the females 

 than in the males, this part in the male (PI. XVIII, fig. 2) being unusually 

 small (as compared with other species); antennae a little more than twice as 

 long as head, 14-segmented; forelegs not much shorter than middle legs 

 either in female or male, hind tibiae with spurs, others without, ungues 

 strong and with a few longish spiny hairs at base; wings (PI. XIX, fig. 2) 

 with typical venation of Blepharocera, that is, with M^ incomplete ( incom- 

 plete vein in the hind margin), no cross-vein between media and cubitus 

 (no cross-vein between veins four and five), and 7?2 wholly fused with R^ 

 (second vein simple without branch); body without special markings, pale 

 fuscous. 



Length, male 4-5 mm.; female 5-6 mm.; the smallest member of the 

 family so far known. 



Described from several males and females dissected 

 from pupal cases (these specimens certainly showing all 

 the characteristic imaginal characters except, perhaps, the 

 coloration; also they may not show quite the full length, 

 i. e., size, of free-flying specimens. 



Collected near Mount St. Helena, Napa County, Cali- 

 fornia; larvge and pup^e taken also from a tributary of the 

 North Fork of the Salmon River, near Sawyer's Bar, 

 Humboldt County, California, and from near Castella, 

 Shasta County, California; all of these localities being in 

 the northern third of the State. There are also a few 

 specimens of this species taken from the stomachs of trout 

 from Battle Creek, California. Named for Baron von 

 Osten-Sacken. 



Immature Stages. The larvae ( PI. XX, figs. 3 and 4) when full grown are 

 5-6 mm. long; dorsal surface of body dark, with transverse sutures between 

 the segments broadly whitish, and a whitish spot near the lateral margin of 

 each segment, giving the effect of an interrupted, broad, whitish, longitudinal 

 line along each side of the body; these markings are in some specimens 

 accented so that a strong black and white pattern is formed; in others the 

 whitish is nearly lacking, so that the whole dorsal aspect is nearly uniform 

 blackish; ventral aspect white with the suckers black; lateral processes short; 

 single, and dark-colored. 



The pupse are about 4 mm. long, thus being conspicuously smaller than the 

 known pupae of any other Blepharocerid. The prothoracic dorsal respiratory 

 plates are rather broad and incurved. 



