1921] NATURAL SCIENCES OF PHILADELPHIA. 59 



Although the remaining specimens of the type-series of D. fumi- 

 costa do not agree in all particulars with the specimen described by- 

 Mr. Edwards, yet they are in so close agreement that practically 

 all of the distinctions indicated hold throughout the series. 



Genus ATARBA Osten Sacken. 

 1869. Atarba Osten Sacken, Mon. Dipt. N. Amer., part 4, pp. 127, 128. 



Atarha is a rather small genus of crane-flies that reaches its great- 

 est specific development in the tropics of the New World. The 

 genus has been referred to the old tribe Antochini but the presence 

 of tibial spurs in the typical forms would indicate that the present 

 reference is more nearly correct despite the reduced venation. 



Atarba megaphallus sp. n. 



Antennae of the male elongate; flagellum dark brown, both ends of 

 each segment narrowly pale; wings grayish yellow; Rs short, cell 

 1st M2 small; male hypopygium with the penis-guard greatly en- 

 larged, the apex widened into a hood-shaped structure. 



Male. — Length 5-5.5 mm.; wing 5-5.8 mm. 

 Female. — Length 6.5 mm.; wing 6.2 mm. 



Rostrum brownish yellow. Antennae of the male elongated, 

 longer than ^one-half the body; scapal segments brownish yellow; 

 first flagellar segment pale brown, passing into dark brown before 

 the tip, the extreme apex pale; remaining flagellar segments dark 

 brown, the extreme base and apex of each segment pale to produce 

 a narrowly annulated appearance; flagellar segments elongate- 

 cylindrical, clothed with an abundant erect white pubescence and 

 provided with a few verticils arranged unilaterally. Head pale 

 brow^nish yellow. Mesonotum pale brownish yellow, the prae- 

 scutum without markings. Pleura brown, fading into yellow on the 

 sternum. Halteres pale brown, the knobs dark brown. Legs with 

 the coxae and trochanters obscure yellow; femora obscure yellow- 

 ish, the extreme tips indistinctly darker; remainder of the legs 

 brownish yellow, only the terminal tarsal segments darker brown. 

 Wings with a strong grayish yellow tinge, the stigmal region indis- 

 tinctly darker; veins pale brownish yellow. Venation: Sc short, 

 Sci ending just beyond the origin of Rs; 8cn some distance from 

 the tip of Scx, the latter alone being nearly equal to the short sector; 

 Rs short, but little longer than the deflection of i?4 + 5; i?2+3 almost 

 straight, running rather close to R-,; cell Ri much narrower than 

 Rz at the wing-margin; cell 1st M2 very small, pentagonal; basal 

 deflection of Cui beyond the fork of M. Abdominal tergites obscure 

 yellowish brown; sternites clearer yellow; in the male a conspicuous 

 sub terminal blackish ring on segments five and six, hypopygium 

 obscure yellow. Male hypopygium with the pleurites and append- 

 ages about as in the other species of the genus; penis-guard greatly 

 enlarged, the apex widened and concave above, hood-like. 



