f V. Some Interesting New Diptera. By S. W. Williston. 



Rhynchocephalus Sackenii, n. sp. s . 



Black ^v'ith light yellowish hair. Head broader than thorax, brown- 

 ish black. Front broad, thinly blackish haired on the vertex ; tlie 

 lower pai't, the face, cheeks, and posterior orbits, with thick, bushy, 

 yellowisli while hair, becoming nearly white below. Antenna? short, 

 reddishyellow, base of first joint infuscated, two first joints subquad- 

 rate, third circular. Style of three joints, first joint short, yellowish, 

 second joint twice as long, basal half infuscated, third as long as two 

 first, fuscous. Proboscis reaching the hind coxre, labium black, other 

 ])arts, with the slender minute palpi, luteons. Dorsum of thoi-ax and 

 scutellnm brownish black with yellowish hair ; pleura? and pectus 

 with longer, bushy, grayish white hair. Abdomen short and broad, 

 black ; second segment above, and all the segments upon their sides, 

 with yellowish hair, somewhat intermixed with black at the incisures ; 

 third and remaining segments above with sparse hairs and thick yel- 

 lowish tomentum, wanting upon their anterior borders, giving the 

 abdomen a slightly fasciated appearance. Venter with whitisli pile. 

 Lamellae of the ovipositor slender, black, luteous at extreme base, 

 about as long as intermediate femora. Feet luteous. Femora white 

 tomentose, wath tufts of hair on their undersides near the coxa» ; ante- 

 rior and middle pairs, for their basal two-thirds, and posterior, except 

 extreme tips, black. Anterior and middle tarsi infuscated, posterior 

 more so, blackish. Wings hyaline ; neuration as in the figure : 



Adventitious oblique vein but slightly arcuated, tenninating beyond 

 the middle of the apical half, not continued to posterior border, so 

 that the third and fifth posterior cells are not completely separated ; 

 both cross veins obsolete. Three submarginal cells ; first and second 

 open, slender. First posterior open, second closed, the brief petiole 

 terminating in the end of the costal vein before the tip of the wing, 

 fourth (third of Osten-Sacken) closed, as usual ; third a little shorter 



Trans. Conn. Acad., Vol. TV. 32 May, 1880, 



