NEW MUSCOID FUES FROM THE ANDEAN MONTANYA |53 



In the female from Arizona the fifth abdominal segment shows a small 

 yellow spot at the sides of the black fascia ; on the mesonotum a pair of 

 narrow subpollinose grayish stripes are visible ; in other respects it agrees 

 with the female from California. 



NEW MUSCOID FLIES, MAINLY HYSTRICIID^E AND 

 PYRRHOSIINyE FROM THE ANDEAN MONTANYA 



By CHARLES H. T. TOWNSEND 

 (Continued from page 144) 



Rhachoepalpus argenteus, new species. 



Length of body, 1 3 to 15 mm., not including spines ; of wing, 1 2 to 

 14.5 mm. One female and two males, Verrugas Canyon, 5,500 feet, 

 July 9 and 10, 1 9 1 3, on flowers of Buddleia occidentalis ; one male, 

 Matucana, 8,000 feet, August 1, 1913. 



Difi^ers from Rhach. cinereus in the pollen of thorax, scutellum and 

 abdomen being silvery, of a decided whitish shade, the thoracic vittae 

 quite distinct. Ground color of abdomen reddish on edges and tip, 

 showing through the pollen, also slightly in bristle-row area along hind 

 margin of second and third segments. Hind scale of tegulae more nearly 

 white, with faintly tawny border ; front scale more translucent, with black 

 narrow border and fringe of fine pilosity. 



Type, TD4170 (fly, uterus). 



Quadratosoma, new genus. 



General characters of Epalpus. Description is of male only. Second 

 antennal joint elongate, third about one and one-fourth to one and one- 

 half times as long as second. Second aristal joint short, not over twice 

 as long as wide. Male front at vertex about two-thirds of eye-width. 

 Proboscis slender and elongate, when extended about twice head-height, 

 the part beyond geniculation about one and one-half times head-height. 



Three stemopleural bristles ; four postsutural, and one to three acros- 

 tichal both before and behind suture but the two anterior paurs m each 

 case when present are weak. Scutellum with two lateral pairs of ordi- 

 nary macrochaetae, and erect spinelike macrochaetae on disk and margin, 

 those on margin longest except the median marginal pair. Abdomen 

 subquadrate in outline in male, the anal width but little less than basal 



