304 Annals Entomological Society of America  [Vol. XIV, 
of intersegments one to three, which increases in width and proportion 
according to succeeding intersegments. 
Segment VI. Tergum glabrous, composed of two broad lateral 
plates whose caudal margins approximate, almost fusing across the 
mid-dorsal line, dorsal and ventral borders ragged, indeterminate; discal 
area gradually widening cephalad, hyaline, indefinitely striated by 
rows of spinules; accessory pieces absent; marginals long, diverse, 
distributed in two irregular rows; spiracles wide apart, equalling twice 
the breadth of the sternum, oblique, posterior spiracles situated on the 
caudal margin. Sternum lanceolate, extending for three-quarters the 
length of the segment, spinulose posteriorly; marginals approximate, 
scattered, including two very long sete; conjunctiva spinulose, spinules 
very small and dense, short fine spines sparsely distributed about the 
caudal area. 
Segment VII. Tergum glabrous, somewhat similar in structure to 
segment VI, heavily chitinized along the lateral and caudal margins, 
investing a coarsely spinulated discal area; marginals diverse, dis- 
tributed around the caudal margin irregularly. Sternum, lanceolate, 
attaining the whole length of the segment, gradually tapering to a 
point caudad; marginals few, including two very long setz; con- 
junctiva densely spinulose, short, fine spines sparsely distributed about 
the caudal area. 
Segment VIII. Tergum composed of a heavily chitinized, archlike 
plate, partially enclosing a lightly chitinized, spinulose discal area; the 
lateral plates spinulose cephalad, smooth throughout the caudal half; 
marginals numerous, short, spinelike, scattered across the marginal 
plate. Sternum smooth, composed of two narrow chitinous sclerites, 
broadened toward the cephalic margin thence gradually tapering to a 
fine point caudad; sete few, one or two; conjunctiva spinulose. 
Segment IX. Suranal plate triangular, equilateral, larger than the 
subanal plate; setae approximate, closer together than the width of the 
club; subanal plate spinulose, smaller than the suranal plate; sete 
arranged in a semi-circle, bordering the margin; setule numerous, 
distributed over the entire surface; cerci short, smooth, laterally 
compressed, sessile; setae short and fine; apicals two; sense organs. 
two, situated laterad. 
Chortophila nuda Strobl.* 
Segments and intersegments of equal length, sclerites glabrous 
except for the subanal plate which is spinulose. Intersegments densely 
spinulose, striated, except for the ventral surface of intersegment four 
which is smooth. 
Segment VI. Tergum composed of two broad lightly chitinized 
lateral plates that blend gradually into the more or less constricted 
discal area, ventral margin defined; accessory pieces present; marginals 
diverse, few, evenly distributed, regular; spiracles wide apart, the 
breadth of the sternum, situated along the ventral margin. Sternum, 
elongate sclerite, rounded caudad, gradually tapering cephalad to the 
margin; marginals approximate, around the caudal border. 
