Genus Sabethes. - 32 
transverse ; base of the first sub-marginal nearer the apex of 
the wing than the junction of the sub-costal and costal ; posteric® 

Fig. 179, 
Wing of R. frontosa. @. n.sp. 
cross-vein about one and a half times its own length from the 
mid cross-vein, both of which are longer than the supernumerary. 
Halteres ochraceous ; a few fuscous scales on the knob. 
Length.—6 mm. 
Habiiat.—British Guiana; at Barima River, and Pomeroon 
Mission (Dr. Low). 
Time of capture.—August (British Guiana). ; 
Observations.—Described from two ?’s; they unfortunately 
had the mesothorax denuded; one is perfect otherwise. This 
species certainly deserves generic rank owing to the strange 
structural peculiarity of the frons in the 9 and the other 
characters previously shown. The specimens were taken on the 
river bank in virgin forest on the Barima, about 70 miles from 
the coast, by Dr. Low. 


Genus 44. SABETHES. Robineau-Desvoidy. 
(Essai s. 1. tri. des Culicides (1827), Rob.-Desy. ; Brit. Mus. List, i. I. (1840), 
Walker; Dipt. Arg., xi. p. 66 (1891), Arribalzaga; Mono. Culicid, Tes 
p. 247, and IT., p. 345, Theobald.) 
(Plate XIV.) 
Head clothed with flat scales and with very short upright 
forked scales ; palpi short in both sexes; antennae pilose in the 
9, rather plumose in the ¢ ; thorax clothed with short flat 
scales ; metanotum with chaetae. Wings rather long and narrow, 
with broad scales ending asymmetrically, fork-cells long, posterior 
VOL. IIL. Y 
