MEMOIRS OP THE NATIONAL ACADEMY OF SCIENCES. 49 



Compared with S. terricola Simon, from Corsica, which also lives under very large stones, and 

 is found common at Porto- Vecchio after the heavy spring rains, bat which has not yet occurred in 

 caves, our out-of-door form is much stouter, with much shorter legs, and also differs in its well- 

 developed eyes, dark brick-red tegument, aud dark markings. It was discovered in Colorado in 

 1874 by Mr. Ernest Iugersoll. while attached to Hay den's Geological Survey of the Territories. 

 He tells me that it did not occur in any cave, the exact locality aud mode of life being forgotten. 

 It will most probably be found under stones. 



Compared with Phalangodes flavescens (Erebomaster flavescens Cope, Amer. Naturalist, vi, 

 420, 1872, from Wyandotte Cave, Indiana), which is allied to the European 8. piochardi, which 

 inhabits caves near Orduuo, it differs in the basal segments being much more distinct, where the 

 sutures in the tergnm are obsolete in 8. flavescens. The eye-tubercle is ajittle smaller proportion- 

 ately, while the eyes themselves are much larger. The mandibles and maxillae are shorter, while 

 the legs are very much shorter and stouter. The color is deep red, the cave species being pale 

 yellow. These are all differences such as we should expect to find between a cave dweller and 

 one which has lived out-of doors under stones, etc. In these two species we have forcibly brought 

 before us the great structural differences brought about by striking changes in the environment of 

 the two species. 



Phalangodes flavescens (Cope). Plate XII ; Plate XIV, fig. 1. 



Erebomaster flavescens Cope. Amer. Naturalist, vi, 420. Figs. 114, 115. July, 1872. 

 Phalangodes flaveseens Simon. Arachnides de France, vii, 156. 1879. 



Male and female specimens. Body broad and stout, uniformly straw yellow, including the 

 body aud appendages. Cephalothorax broad and short, but little longer than broad, the sides 

 widening a little toward the hinder edge, being wider on the hinder edge than elsewhere; it is 

 somewhat constricted on the anterior third just behind the eyes; the surface is considerably 

 rounded, the posterior edge is quite free and distinct from the abdomen ; the latter is unusually 

 short aud broad, with three segments visible from above and six, in all, beneath, the basal one 

 being the longest. The eye-tubercle is large and high, usually forming a cone slightly higher than 

 broad at the base. The two eyes are black, distinct, and situated on each side, near the base of 

 the conical tubercle. The cornea is underlaid by a broader dark mass forming the retina. Cheli- 

 cerae with the first joint rather long aud slightly contracted iu the middle; the second joint or 

 hand is rather thick, not twice as long as thick ; the outer. finger is much larger than the inner, 

 much curved aud pointed, with a series of ten small conical teeth on the inner edge ; the inner 

 tooth is straight, with five large bluut teeth on the inner edge. Three "short setae can be seen on 

 the outer half aud two on the inner side near the fingers. Pedipalps less than twice as long as 

 the body, but nearly twice as long as the cephalothorax; coxal joint very broad and short; first 

 joint longer than broad, cylindrical, with a small setiferous external spiue in the middle, and on the 

 inside an anterior much larger spine bearing a bristle; second joint longest of all, with four sub- 

 equal setiferous spines on the outside; on the inner side two large spines, the first half as long as 

 the joint is thick, and bearing- a stout movable spine as long as the joint is thick; the second spiue 

 is somewhat smaller; these are succeeded by four very small spines situated on the proximal half 

 of the joint, wliile the edge, especially in the middle, is finely toothed; on the distal end is a group 

 of three unequal spines, one large and long; third joint a little more than half as long as the 

 second, with five or six unequal spines visible on each side, two of them being as long as the joint 

 is thick ; joint four is somewhat elongated, barrel-shaped, with four stout spines on the outer and 

 three on the inner edge, the latter being long and slender, with long setae, the basal one as long 

 as the joint is thick in the middle; the fifth aud last joint has four external stout curved spines, 

 and three large and two minute straight inner spines; four of the setae, though differing iu length, 

 are a^ long as the joint is thick; the terminal spine is shorter and thicker than the others, with a 

 movable seta, which is as long and fully twice as thick as the others. 



First pair of feet much smaller and shorter thau the second pair, the last tarsal joint four- 

 joiuted ; second pair slenderer than the fourth pair; the third joint uot so much swollen; the last 

 tarsal joint divided into twelve joints ; length of entire leg, 8 mm ; third pair a little longer than first 

 S. Mis. 30, pt. 2 4 



