86 THOMAS SAY FOUNDATION 
thoracic legs; three pairs at the postero-lateral base of the meta- 
thoracic legs; one pair on the lateral conjunctivae between the 
pro- and mesosternum, and one pair in a similar location between 
the meso- and metasternum. Anal gills absent. In the male 
nymphs the ninth sternite is somewhat produced, and in mature 
nymphs the elongate ‘‘hammer’’ is noticeable. The female nymphs 
are larger than the males, the ninth abdominal tergite is not 
much produced and the developing genital opening is plainly 
indicated in the middle of the posterior margin of the eighth 
sternite. 
Mouth parts of the carnivorous type and very similar in struc- 
ture to the mouth parts of other species in this genus. 
This species has not been reared, but I have before me a num- 
ber of mature nymphs in which the genitalia can be clearly seen, 
and this has made possible the identification. 
Nothing is known of the life history or biology of this species, 
but the life cycle probably is not completed in less than three 
years. 
Eel R., Calif.; Evey’s Canyon, Calif.; San Jacinto, Calif.; San 
Antonio Canyon, Claremont, Calif.; Logan R., Utah. 
Acroneuria depressa (?) Needham and Claassen 
(Plate 27, fig. 207.) 
Length of body up to 31 mm.; antennae up to 15 mm.; cerci 
up to 20 (?) mm. 
Head about as wide as pronotum; ocelli very large, hind ones 
closer to each other than to the eyes; between the transverse dark 
band, which passes through the ocellar triangle, and the lateral 
arms of the epicranial suture, there are three inverted V-shaped 
yellow spots; one between the ocelli and one outside of each hind 
ocellus; occipital ridge strongly developed and uniformly prom- 
Inent across the occiput; antennae about half as long as body 
and made up of about eighty to eighty-five seements; surface of 
head with many short brown hairs. 
Pronotum about twice as wide as long; hind angles very broad- 
ly rounded, front ones more narrowly so; lateral dises yellow with 
brown markings; marginal groove distinct and continuous; entire 
margin of pronotum dark brown around the edge. 
Meso- and metanotum with a variegated pattern of yellow and 
brown, covered with short brown hairs, and the outer fields of the 
wing pads with short spinules. Legs flattened; yellowish with a 
transverse brown band across the middle of the femora, and the 
