216 NEW YORK STATE MUSEUM 
number of cross veins in any part, but in general they are more 
numerous in the female. Behind the costal brown band in the) | 
female there are about 70 cross veins, not in a single row, not in 
regular rows at all. q 
Abdomen pale yellowish or flesh tinted, thickly dotted and 
dashed with brown, tending to form a dark middorsal band, more. 
or less completely divided on the base of each segment, a line of 
brown dashes each side just above the pale lateral margin on)| 
segments 1-9, with a more or less separate curved mark above 
the anterior end of each dash. At the sides the metathorax)| 
overlaps the first abdominal segment and almost reaches the}| 
base of segment 2. The ventral side of the abdomen is paler with) | 
more uniform dots and a pair of submedian brown ()- marks | 
Fig. 2 End of abdomen of Callibaetis skokiana, male, ventral view, showing 
forceps, rudimentary median caudal filament and bases of lateral filaments 
on segments 2-9, abbreviated on segment 9. Forceps of the }y 
male [figure 2] and setae of both sexes pure white. - 
Subimago. Differs in having the setae shorter (about 9mm 
long in both sexes), the wings faintly smoky brown, or slightl 
tinged with yellowish on the middle of what is to be the cost 
al 
ne and the principal bands of brown on the body faintly indi- 
cated. ? 
Nymph. Length of body 12-13mm, setae 6-7mm additional; | 
width of head 1.2mm, of thorax 1.8mm. Color greenish, marked : 
with pale fuscous. at 
Head pale, suffused with brownish around the eyes and across \f 
the ocelli in front, a longitudinal band bounding each eye inter- | 
nally, tinged with yellowish. ih 
Prothorax pale marked with fuscous on the front margin and | 
at the sides, with a pair of pale spots in irregularly contoured | 
brown inclosures on the dorsum. Mesothorax and metathorax } 
darker dorsally with pale markings at the front margin and at | 
