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MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
either edge; the spines are all tipped with long bristles, bent towards and crossing those of the opposite row. The 
male *organ is cylindrical, without joint or median swelling, as thick as the coxae, not chitiuous, bearing at tip a few 
fine hairs; when fully protruded it equals one-third of the body in length. The abdomen shows but four narrow and 
one conical terminal segment beyond the cephalothoracic shield. The conical eminence at the anterior border of the 
dorsum, between the first pair of legs, is without trace of ocelli. Length without appendages, 2™ m = .08 inch; 
longest leg, 18 mm = .72 inch. 
Two specimens in alcohol from Martha’s Vineyard, in the Mammoth Cave. 
Fig. 14 _Phalangodes armata : as, claw of anterior tarsus; b, claws of posterior tarsi; c, enlarged ten times (after Hubbard). 
Remarks.— This form, though living in Mammoth and adjoining smaller caves, and sometimes 
occurring near daylight, seems to undergo almost no variation, either as regards the absence of 
any traces of eyes or the remarkable leugth of legs. It is the extreme in a series of forms, including 
Phalangodes flavescens, var. ceeca, iceyeremis , and the terricolous P. spinifera, with the very stout 
short-legged P. robusta. Without much doubt P. armata has been derived from a form like P. 
spinifera ; or from au earlier terricolous species, from which both diverged. 
_ -Phalangodes spinifera, u. sp. Plate XIII, figs. 2, 2 a, 2b, 2c. 
One female. Body rather broad and stout; more contracted ou the sides behind the inter- 
ocellar spine than in P. robusta. Cephalothorax widening considerably behind the hinder edge; 
it is two-thirds as long as the body. The eyes are considerably smaller than in P. robusta, black, 
and placed unusually far apart; between them is a conical projection ending in a high, sharp 
prolonged spiue. There are five abdominal segments seen from above, the fifth narrow, conical 
minute. The surface of the cephalothorax is rough, with sharp granulations, and the hind edge’ 
with that of the succeeding segments, are adorned with a row of sharp spines, the median ones 
largest, those on the fourth segment being more numerous, large, aud sharp, with a group of about 
five large ones of unequal size on each side of the body. 
The chelicerm are 2.5 mm long, much longer and slenderer than in P. robusta-, but closely like 
those of P. armata from Mammoth Cave, the first joint being similarly contracted toward the base; 
* This appears to be the ovipositor of the female. 
