WILLISTON: NEW DIPTERA. • 63 



Pachyrrhina erythrophrys, n. sp. 



Male. Black, shining, the posterior orbits and the second, third 

 and fourth abdominal segments, except their margins, orange red. 

 Antennae black, somewhat longer than the thorax, the second and 

 following joints of the flagellum with a distinct enlargement at the 

 base, from which the short verticils arise. A ridge, contiguous with 

 the eyes posteriorly, meeting in the middle just back of the antennae 

 and extending to about the middle of the sides of the head, orange red. 

 Thorax shining black throughout; halteres black. Abdomen shining 

 black; the second, third and fourth segments, except the narrow 

 lateral and posterior margins, orange red; on the venter, the anterior 

 portion of these segments is of the same color. Legs black, with the 

 base of the femora yellow. Wings blackish; second posterior cell 

 sessile. 



Length, 13 mm. 



One specimen, Manitou Park, (Colorado, Prof. F. H. Snow. 



Ctenophora angustipennis Loew. 



Male. Head and antennae black, the palpi and second and third 

 antennal joints yellow. Antennae about as long as the mesonotum, 

 the pectinations scarcely exceeding the antennal joints in length, 

 of equal length on the inner and outer sides, the twelfth joint with two 

 pairs as in the preceding joints; the first pair on the third joint short 

 and obtuse. Mesonotum yellowish red; the lateral margins and a 

 spot in the middle behind black; the humeral callosity, the pronotuni, 

 and a stripe on the upper part of the pleurae, running through the 

 root of the wings, yellow. Scutellum on the sides, the upper part of 

 the metanotum, and the metapleurae in front of the halteres, yellow; 

 scutellum and pleurae, otherwise, black. Abdomen yellowish red, 

 with a continuous black stripe, expanded on the posterior part of each 

 segment. Legs yellow; the extremity of the femora and tibiae, and 

 the distal three or four joints of the tarsi, dark brown. \Vings light 

 amber-colored. 



I>ength, I 7-20 mm. 



Two specimens, Washington, LIniversity of Kansas. 



Ctenophora similis, n. sp. 



Male. Resembles C. a>!i:;i/sf//)C>iuis, but differs in the mesonotum 

 being shining black, except the small humeral callosities; in the black 

 of the abdomen being more extensive, and in the greater infuscation 

 of the legs. 



Length, 19-21 mm. 



Two specimens, Washington, LIniversity of Kansas. The black of 

 the abdominal segments extends outwardly on the posterior part, so 



