ZooL— Vol. III.] KELLOGG— NET-WINGED MIDGES. 1 93 



4. ^ Bibiocephala elegantulus von Rdder. 



Plate XVIII, Figs. 4 and 5; Plate XIX, Fig. 5; Plate XX, 

 Figs. 9 and 10; Plate XXI, Fig. 7; Plate XXII, Figs. 7 and 8. 



Eyes ( PI. XVIII, fig. 5) of male separated rather widely, and bisected by a 

 narrow line, the upper, large-facetted portion of the eye being one-fourth of 

 the whole eye; in female (PI. XVIII, fig. 4) the eyes are separated by a narrow 

 space, and bisected by a line, the upper, large-facetted portion forming about 

 one-third of the whole eye; antennae 14-segmented, and about one and one- 

 half times as long as head; hind legs longer than subequal middle and fore- 

 legs, hind tibiae with spurs, middle tibiae with very small spurs, fore tibise 

 without spurs, ungues rather strongly curved, not incrassate; wings (PI. XIX, 

 fig. 5) with a cross-vein between media and cubitus (connecting veins four 

 and five) with Rj^ present as a very short vein running so quickly into R^ as 

 to form a nearly equilateral triangle (a short anterior branch of the second 

 vein running into the first vein close to the origin of the second vein); R^ and 

 R^ usually arise from a common point but are not Stemmed, a short stem, 

 however, sometimes being present, and in this case there may be a cross-vein 

 connecting the two near the point of forking (veins two and three usually 

 sessile but occasionally having a very short stalk); a short subcostal vein 

 (auxiliary) is usually indicated; dorsal and lateral aspects of thorax dark 

 brown, ventral aspect whitish; dorsal aspect of abdomen dark brown, with 

 narrow, transverse sutural lines, ventral aspect whitish; legs pale brown; 

 antennae and head except the red-brown, upper, large-facetted portion of 

 eyes blackish. 



Length of male 8.5 mm.; female iq mm.; body of female (PI. XXI, fig. 7) 

 much more robust than in male. 



Described from numerous free-flying males and females 

 taken in July and August, 1900, from Big Thompson River, 

 at the mouth of Willow Park, altitude 7,500 feet, in Estes 

 Park, Larimer County, Colorado; same species found also 

 in Wind River, Mill River, and South Fork, streams tribu- 

 tary to the Big Thompson. Originally described by von 

 Roder as a new genus, Agathon, from Nevada. Aldrich 

 has found it in Idaho. 



1 In the paper as sent to the printer, the writer had described this as a new species, 

 being led to do this by von Roder's contradictory account of the venation ot Affaihon, 

 Von Roder's account deceived also Osten-Sacken and Williston, who thus wrongly enter 

 Agathon in their synoptic tables. Professor Aldrich, however, called the writer's atten- 

 tion to the fact that although von Roder uses the word "pone" instead of "ante" in his 

 Latin description of the species, in his German description of the genus the contrary 

 (and true) condition is properly described. Von Roder also unfortunately gives an 

 ambiguous locality for his species in the words " Patria: (Sierra) Nevada, America 

 sepentr. (Morrison)." In a letter to Professor Aldrich, Baron von Osten-Sacken states 

 that Morrison found the specimens in the State of Nevada and not in the Sierra Nevada 

 (mountains of California). 



