Dec, iQi-'.] Alexander: Revision of Brachypremna. 235 



Hab. Cassapava, Brazil. (Sellow, Coll.) 

 " Type in Berlin Museum." 

 Adapted from Osten Sacken's original description, /. c, p. 239. 

 Brachypremna unicolor Osten Sacken. 

 1887. Brachypremna unicolor O. S., Berl. Ent. Zeit., Vol. 31, pt. 2, pp. 239-240. 



1900. Brachypremna unicolor Hunter, Trans. Am. Ent. Soc, Vol. 26, p. 285. 



1902. Brachypremna unicolor Kertesz, Cat. Dipt., Vol. 2, p. 265. 



Head : rostrum light brown ; nasus concolorous, with short hairs ; palpi, 

 basal segment, brownish at origin, paler apically ; second segment pale ; re- 

 maining segments brown. Antennae, first segment brown; second segment 

 much lighter colored, yellow; flagellar segments dark brown with the extreme 

 tip yellow, producing an annulated appearance, this coloring becoming obsolete 

 near the end of the flagellum. Front, vertex and occiput light yellowish-brown. 



Thorax : prsscutum light brown, the anterior portion of the sclerite suf- 

 fused with brownish, concealing the usual stripes ; two distinct brown dots on 

 the extreme cephalic margin of the sclerite; on the caudal portion of the 

 sclerite, the dark stripes become distinct; median dark stripe not double; 

 scutum uniformly light brown with suggestions of darker lines ; scutellum and 

 postnotum pale, with a narrow brown median line and with the lateral edges 

 of the sclerite indistinctly brown. Pleurae uniformly pale without distinct darker 

 marks. Halteres long, brown, pale at the base of the stem. Legs : coxje pale, 

 femora light brown passing into dark brown at the tip ; tibia dark brown, the 

 extreme base slightly paler, but not producing a ringed appearance ; tarsi 

 slightly lighter brown. 



Wings: almost hyaline; cell C light yellowish-brown or yellow; cell Ro 

 tinged with yellow along the costal margin ; cell R, tinged with yellow at the 

 tip ; veins narrowly margined with pale brown ; darker brown clouds at the 

 ends of the radial veins ; stigma very pale brown with a narrow border of 

 darker brown. Venation (see Fig. c) : Rg long, beyond the arcuation, about 

 three times as long as Mj+j between cross-veins r-m and m ; basal deflection 

 of i?4+5 none, so that R^+s is in a line with Rg and R^+a and i?4+5 arise directly 

 from the end of the sector; cross-vein r-vt short but distinct, petiole of cell 

 Ml very short; cell ist M^ sub-triangular; fusion of M3 and Cu^ very slight; 

 basal deflection of Cu^ at, or before, the fork of M. 



Abdomen : tergum dark brown, the bases and lateral margin of the seg- 

 ments indistinctly paler ; sternum pale, with the median spots on the segments 

 very elongate, black, forming an almost continuous line ; lateral margins of the 

 sclerites, darker, brownish. 



5, length, 1 6.5-1 8.6 mm.; wing, 1 8.5-20.1 mm. Fore leg, femur, 11.8 mm.; 

 tibia, 13.3 mm. Hind leg, femur, 13. 8-14 mm.; tibia, 15.4-16 mm. 



Distribution. — Island of Cuba, Cayamas (E. A. Schwarz) ; Is- 

 land of Porto Rico (Moritz) Osten Sacken's types; Island of Grenada, 

 Lesser Antilles (Busck.) 



