94 
Psyche 
[June 
and support several long fine hairs. The female genital area 
is oval (fig. 8), situated a little above the center of the body and 
enclosed by the inner ends of the epimera as well as by the 
posterior plate. The valves of the opening are also heavily chi- 
tinized and bear hairs; they show more conspicuously than in 
the male a division into an anterior inner part and a posterior 
outer part, the latter showing numerous circular acetabula. One 
female (fig. 9), was found with the large ovipositor extended 
through the genital slit. This organ is a delicate, light colored 
structure within which could be seen the outlines of the nearly 
circular eggs. 
The palpi (fig. 4, 5, 8) are very small and appeared always 
within the enclosure formed by the united first pair of epimera. 
They are flattened and are borne on the sides of a slender capi- 
tulum near the top. A conspicuous feature is the presence of 
two long curved doubly bifid bristles on the distal end of the 
second segment. 
The legs are short, stout, increasing in length from first to 
fourth. The first three pairs are much like those of the related 
species and show the same partial union of the first two segments. 
They bear many heavy bristles, but these are somewhat longer 
than in the Asiatic form. All end in large double claws, orange 
red and beset with teeth on the curved side. The fourth leg in 
the female (fig. 6) is similar to the third but longer; in the male 
it is considerably modified (fig. 3) and doubtless used as a 
copulatory organ. The last three segments here are flattened, 
the fourth showing a plate-like expansion on the inner side; the 
last two segments are thickly beset with stiff hairs, the fifth 
being the longest and the sixth not much shorter, but broader 
with the claws lacking the teeth. 
The types were secured in two collections from Nevada, a 
total of nine individuals. 
Three males and four females were found in water of tem- 
perature of 43 °C., fifteen miles north of Deeth; and a young 
male and a female in temperature 42.5°-45°C., in the Valley 
Hot Springs at Minden. 
The new species is seen to be closely related to the Asiatic 
