314 Annals Entomological Society of America  [Vol. XIV, 
area of each lateral plate and the anterior portion of the median sclerite, 
included amongst the spinules are a few short sete; conjunctiva 
reduced to narrow articulating membranes between the sternites and 
the tergites. 
Segment IX. Suranal plate broad, transverse; sete long, wide 
apart; setule scattered; subanal plate spade-shaped; setz distributed 
apically, setulz distributed over the entire surface; cerci spinulose, 
knobbed, sessile; apicals strong; setulze short, fine, distributed on the 
distal region of the club. 
Pegomyia trilineata Stein. 
Segments longer than the intersegments. Sclerites glabrous except 
the sternum and accessory pieces of the sixth segment which are partly 
spinulose, and the subanal plate which is wholly spinulose. Inter- 
segments smooth, hyaline. 
Segment VI. Tergum lightly chitinized, with thicker areas along 
the caudal, cephalic and lateral margins. These plates blend imper- 
ceptibly into a large semi-translucent discal area. Marginals short, 
diverse, more or less regular; accessory pieces present, partly spinulose; 
spiracles oblique, adjoining the accessory pieces. Sternum spatulate, 
cephalic half but faintly chitinized, at the tip of which is a pair of sen- 
sory organs, caudal half spinulose, hexagonal in outline; marginals in 
two lateral groups; conjuctiva spinulose on the caudal half, hyaline 
and smooth cephalad. 
Segment VII. Tergum divided into two lateral plates that fuse 
across the caudal margin; discal area large, semi-translucent, confining 
the plates to the lateral margins of the segment; marginals as in 
segment VI; accessory pieces present. Sternum spatulate, glabrous, 
with but a few if any spinules; marginals and sense organs as in seg- 
ment VI; conjunctiva smooth, hyaline, with a very few spinules along 
the caudal margin. 
Segment VIII. Tergum completely and heavily chitinized, encasing 
the dorsal region, cephalic margin emarginate, a short chitinous tooth 
at the caudal end of the middorsal line; marginals short, diverse, 
irregular. Sternum composed of two strongly chitinized, elongate plates 
reaching three-quarters the length of the segment; sete short, confined 
to the caudal third of the sternites; conjunctiva, smooth, semi-opaque. 
Segment IX. Suranal plate scoop-shaped, setze short, approximate; 
subanal plate spade-shaped, setze normal, setulz long around the caudal 
margin, short and thornlike on the plate; cerci glabrous, subcylindrical, 
petiolate, apicals one per club, setulee short, distributed on the club and 
petiole, at the apex of the former are two strikingly recurrent setule. 
Pegomyia trivittata Stein. 
Segments longer than the intersegments. Sclerites glabrous except 
the sternum of the seventh segment which bears numerous stout, 
short spines. Intersegments heterogeneous; the first smooth on the 
dorsal surface, on the ventral surface spinulose throughout the cephalic 
half, smooth caudad; second intersegment spinulose, densely so along 
