98 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



upon the bottom of the box. The fore legs were extended forward so that 



the feet came well together, each leg being fastened upon a thread. The 



cephalothorax and head were bolstered against several cross 



Other lines. When the observation began the skin of the corselet was 



loose and cast back above -the abdomen. The spider was in 

 jjinypnia. 



the act of moulting the face below the eyes and falces. This 



was done by a succession of regular motions by which the body was 

 pressed backward against the moulting frame, and the skin of the 

 legs, palps, and falces at each swell was pushed a little more forward. 

 The purchase was less as the skin was more and more rejected, and 

 at the metatarsus and tarsus the legs were extricated by pulling them 

 gently. 



After moulting the legs were folded together under the sternum, and 

 were then passed through the mouth in the manner of spiders when 

 cleansing the hairy armature of the legs. The new skin looked 

 Behavior fpggjj an( j bright ; the black rings upon the legs retained their 

 j, e r, . hue ; the flesh colored and brownish parts were whitish ; the 

 abdomen was little changed as to color. Shortly after moulting 

 the spider turned over and assumed an upright position upon her moult- 

 ing frame. When touched she kept quite still, decidedly in contrast with 

 the normal habit of the species. 



The Medicinal spider (Tegenaria medicinalis) suspends itself beneath its 

 web in order to moult. The skin divides at the edges of the cephalo- 

 thorax, leaving the casts of the sternum and the three first pairs 1 

 Medicinal o j \ e g s , together with the mouth parts, on one side ; the shield, 

 jP 1 ff s abdomen, and last pair of legs on the other. In the cast skin 

 the corselet is thrown backward and downward, and is surrounded 

 by the hind pair of legs. It is united to the abdomen, which is repre- 

 sented by an irregular mass of black skin, the softness of that organ 

 preventing it from maintaining the firm outlines of the other parts, which 

 more resemble the shell of true insects. The skins of the first three pairs 

 of legs are thrown forward, nearly or quite touching above the face, as 

 when one throws his arms over his head. 1 This represents the position 

 maintained during the act of casting the skin. 



With Trochosa singoriensis the rejected dorsum of the cephalothorax is 

 held to the abdomen by the skin of the pedicle, which is rent longitudi- 

 nally into two nearly equal parts. The upper part unites the 

 ycosi s. corse } e j. fo ^ ne abdomen, and the lower part ties the sternum 

 thereto. The cephalothorax parts along the edge above the inser- 

 tion of the legs ; the last pair of legs first escape from the old skin, then 

 the third, and the others in order. In unsheathing the legs the spider 

 finds a point of support in the legs themselves; that is, she supports 



1 This may not be the rule, but is true of the case described. 



