56 
MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
it is oval and somewhat flattened. The body is white, the appendages being slightly dusky. The 
eye prominence is rather large compared with that of N. troglodytes Pack. The eyes are wanting, 
the pigment being colorless, but with a dark line indicating the traces of a retina. Glielicerse 
slender, rather long, the inner edge of each Anger with short, stiff setae; on the upper side, at the 
base of the immovable finger, are two straight, stiff - hairs; the hand is not setose, as in that of 
N. troglodytes. The pedipalps are only of moderate length, being, in proportion, only about oue- 
third as long as those of N. troglodytes; the second joint is not much longer than the basal, being 
slightly longer than thick; third joint three times as long as the second ; third and fourth ’of the 
same length, but the tourth a little thicker; fifth slightly longer and thicker than fourth, with 
numerous stout setae of nearly even length; sixth (terminal) two-thirds as long as the fifth and 
nearly as long in proportion as the terminal joint in N. troglodytes ; it is very setose and the tip 
is rounded. Legs of second pair 3 mm in length, hairy, last tarsal joint undivided; fourth pair 4 mm 
in length, the last tarsal joint with nine subjoints, and the ungues smaller than in the second 
pair. 
Length of the body, including the cheliceres, l mm 
Locality, Bat Cave, Carter county, Kentucky. 
The specimens found were immature, but the species is so characteristic that I have ventured 
to describe it. It differs from the Utah N. troglodytes chiefly in the much shorter pedipalps, with 
proportionally much shorter joints in its naked hand and much slenderer legs. The specific 
name is given it in allusion to its feebly-developed, degenerate eyes. It is the first species of the 
genus known to occur in the eastern United States. • 
AEANEINA. 
It is in the small caverns of Carter county, Kentucky, and the two Weyer caves (Weyer’s 
and the adjoining Cave of the Fountains), which are often but a few (less perhaps than a hun¬ 
dred) feet below the surface, that the variation and number of species of spiders is greatest. In 
each set of caves there are three species to one in Mammoth and Wyandotte caves. The individual 
variation was the greatest in Nesticus pallidus, and, as might be suspected, in the eyes. The 
degree of variation is indicated in Mr. Emerton’s descrjption. 
The spiders occurred more abundantly in all the caves than we expected. The individual 
abundance was greater in the smaller caverns, especially the Weyer caves, than any others. In 
the Mammoth Cave the Anthrobia occurred under stones in dry, but not the driest, places on the 
bottom at different points in the cave. Sometimes two or three cocoons would be found under a 
stone as large as a man’s head. The cocoons were orbicular, flattened, an eighth of an inch in 
diameter, and formed of fine silk, and contained from two to five eggs. They occurred with eggs 
in which the blastodermic cells were just formed April 25. The eggs were few in number and 
seemed large for so small a spider, beiug x |f „ inch in diameter. The chorion is very thin and 
finely speckled. The blastodermic cells seemed very large, the largest measuring nearly T 0 ±-_ inch 
in diameter. They were round, not closely packed, and showing no indications of being polygonal. 
They all had a dark, very distinct nucleus. I was unable to trace the development of the young 
and ascertain if the embryos are provided with rudimentary eyes. Two young Anthrobise hatched 
out May 3 in my room. The whole body, including the legs, is snow-white, with the legs much 
shorter - than in the adult. The adult in life is white, tinged with a very faint flesh color, with the 
abdomen reddish. In some specimens the abdomen has beneath several large transverse dusky 
bands. The Linyphia subterranea , as observed living in Wyandotte Cave, is pale pinkish, horn- 
browu on the thorax and legs, while the abdomen is dull honey yellow. 
What constitutes the food of these diminutive, weak, sedentary spiders I can not conjecture, 
unless it be certain minute delicate mites or young Podune, They spin no web, though some of 
the spider’s in Weyer’s Gave (Gave of the Fountains) do spin a weak, irregular web, consisting of 
a few threads. The Sciarse and Ohirouomus are too large and bulky to be captured by them. The 
probable insufficiency of food as well as light may account for their small size and feeble repro¬ 
ductive powers. The individuals were far less numerous than those of the Phalangodes and 
Ghernetid®. 
