300 Annals Entomological Society of America  [Vol. XIV, 
ent; marginals few; spiracles contiguous, slightly oblique, directly 
cephalad of the accessory pieces. Sternum reduced to two round chit- 
inous areas that have fused and lie adjacent to the caudal margin of 
the segment; marginals wide apart, arranged into two groups; con- 
junctiva hyaline, transparent. 
Segment VII. Tergum composed of two narrow chitinous strips, 
flaring caudad and extending the length of the segment along the 
subdorsal axes; discal area hyaline; accessory pieces present; mar- 
ginals few and stout. Sternum, similar in structure to segment VI, 
pointed cephalad; marginals widely separated into two groups; con- 
junctiva hyaline. 
Segment VIII. Tergum similar in structure to that of segment VII; 
the tergites broaden more noticeably caudad; marginals more numerous; 
discal area hyaline transparent, the sides of the segment clothed for the 
greater part with scalelike spinules. Sternum composed of two narrow 
sternites, oar-shaped, subparallel, extending along the subventral axes 
for the length of the segment; sete two; conjunctiva hyaline. 
Segment IX. Suranal plate hemispherical; setae stout, setulae few; 
subanal plate spinulose, spade-shaped, setze normal; setule sparsely 
distributed; cerci small, glabrous, knoblike; setz consist of one strong 
apical seta, setulz spinelike. 
Chortophila dissecta Meigen.* 
Segments slightly longer than the intersegments, breadth exceeds 
length. Intersegments; vestiture not uniform, first intersegment spin- 
ulose, second and third the ventral surface spinulose with narrow dorsal 
stripes along the cephalic margins, fourth intersegment spinulose on the 
ventral surface, smooth dorsal region. 
Segment VI. Tergum spinulose, composed of two broad enveloping 
plates that are linked together across the mid-dorsal line by a thinly 
chitinized discal area; accessory pieces present; marginals diverse, 
arranged in an irregular row; spiracles, the width of the accessory piece 
apart, oblique, posterior spiracles close to the caudal margin of the seg- 
ment. Sternum spinulose, expansive, whose margins are indeterminate, 
gradually fading into the surrounding membrane; marginals diverse, 
scattered about the caudal border; conjunctiva spinulose. 
Segment VII. Tergum glabrous, divided into two lateral plates, 
each extensively bordering the caudal margin, almost fusing across the 
mid-dorsal line, thence forward gradually tapering to a rounded apex, 
not quite reaching the cephalic margin of the segment; discal area 
hyaline, smooth, widely separating the tergites cephalad; accessory 
pieces present; marginals diverse arranged in an irregular, row. Sternum 
spinulose, a short, indeterminate plate; marginals in a transverse row; 
conjunctiva spinulose, on the mid-ventral line adjacent to the cephalic 
margin is found a small chitinous thickening bearing two stout spinules. 
Segment VIII. Tergum glabrous, composed of two lateral pieces 
whose caudal margins have fused dorsad to form a marginal plate, the 
tergites extend dorsocephalad toward the cephalic margin, bordering 
a smooth, hyaline discal area; marginals diverse, in an irregular row. 
