F. R. COLE 67 



June and August. One pair was taken in copula, April 25, 1912, 

 by E. A. Schwarz. Mr. E. T. Cresson, Jr., loaned a pair taken in 

 copula, June 18, 1905, at Swarthmore, Pennsylvania. 



Ogcodes marginatus new species (PI. XV, fig. 42.) 



cf. Eyes, head and thorax black. Antennae black. Frons black and not 

 prominent, with a few short white hairs. Few white hairs on sides of face. 



Thorax, pleura and scutellum black, semi-shining and with fine white pile. 

 The pile is unusually long and dense for an Ogcodes, that on the thorax in 

 certain lights almost obscuring the ground color. Humeral and praescutellar 

 callosities black. Squamae white with pale rims; there is a narrow hyaline 

 space between the rim and the white color of center of squamae which is very 

 noticeable. 



Abdomen black, the posterior margin of the first segment narrowly white. 

 Posterior margins of other segments wide (see fig 42). Abdomen clothed with 

 erect whitish pile. Venter white, the segments with a brownish black basal 

 stripe, rather narrow except on first two, and suddenly widening near the lateral 

 margins. Genitalia black. Coxae and femora black, apical third of femora 

 yellowish. Tibiae yellowish, basal two-thirds darkened on outer side. Tarsi 

 blackish and rather short, especially first joint. Femora with fine white pile. 

 Wings hyaline. Costa and veins at base of wing brownish, yellow the rest of 

 their length. 



Habitat. — Upper Geyser Basin, Yellowstone Park, Wyoming, 

 7,200 feet elevation, August 24, 1915. 



Type.- — One male specimen in Cornell University collection. 

 There are two male paratypes in the Kansas University collection, 

 from Clark County, Kansas, June, elevation, 1,962 feet (F. H. 

 Snow). 



A specimen from Fort Collins, Colorado, July 10, 1907, in the 

 collection of C. W. Johnson, is very probably a female of this 

 species. It is near melampus Loew. The white posterior mar- 

 gins of the abdominal segments are very narrow on the first and 

 second segments, gradually wider on the following segments, and 

 rather irregular. 



Three small specimens in the National Museum collection may 

 belong here. These are : one male from Mono Lake, California, 

 June 21, 1911; a male from Los Angeles, California (Coquillett) ; 

 a female from Salt Lake, LHah, June 26 (H. S. Barber). 



Ogcodes albiventris 



Oncodes albiventris Johnson, Psyche, xi, p. 18, (1904). 



"Head black, antennae yellow. Thorax and scutellum black, shining and 

 covered with erect yellowish jiile. Abdomen white, and marked with black as 



TRANS. AM. ENT. SOC, XLV. 



