ate NEW YORK STATE MUSEUM 
Abdomen with a pair of broad, dorsal fuscous stripes inter- 
rupted on the sutures, extending posteriorly to end at the bases 
of the lateral appendages on each side, including a pair of trans- 
versely placed darker spots [fig.16]. On each side, half way 
from this band to the lateral margin, there are on each segment 
a pair of brownish marks, of which the lower one is transversely 
placed and rests on the apical carina of the segment; each lateral 
appendage is black on its lateral margins. 
No dorsal hooks at all. Lateral spines almost wanting, repre- 
sented only on the ninth segment by a very minute tooth, which 
i —, 
. 
od 
Fig. 17 Labium of Sympetrum corruptum 
continues the inward slope of the lateral margin. Sides of 
abdomen nearly parallel on segments 4-7, slightly narrowed 
posteriorly on 8, strongly narrowed on 9; 10 annular, included, 
one fourth to one third as long as 9; superior appendages as 
long as segments 9 and 10 together, lateral appendages fully one 
third shorter than the others; the lateral and ventral margins 
of segments 9 and 10 very hairy. 
This species differs from its nearest relative, S. illotum, 
(1) in having 13-14 lateral setae on its labium [see fig.17], in 
S. illotum there are but 9; (2) in having about 17 mental 
setae, each side of which there are nine in the stronger outer 
series—in il1lotum there are about 13, and seven in the 
stronger outer rank; (3) in haying the lateral spines even less 
developed; (4) in having a better developed color pattern. Ex- 
cept in these particulars the nymph of S. illo tum (of which 
