THE DYSDERIDyE 



The Dysderidae are a small family of spiders resembling in 

 their general appearance the Drassidae, bat differing from them 



in several important characters. They have only 

 six eyes instead of the usual eight, and they have 

 four breathing holes in the front of the abdomen, 

 two of them leading to the usual lungs and the 

 others to the air-tubes, which in most 

 spiders open just in front of the spin- 

 nerets. 



Dysdera interrita. — Six eyes close 

 together on the front of the 

 head. Length half an inch, 

 with the abdomen a little 

 longer than the cephalothorax. 

 The coxae and patellae are un- 

 usually long, especially on the 

 front legs, and the tarsi are 

 unusually short (fig. 70). The 

 mandibles are long and inclined 

 forward. The maxillae are long, 

 a little widened in the middle 

 and pointed at the ends. The 

 labium is long and narrow, and 

 forked at the end (fig. 72). The 

 skin around the base of the legs 

 is thick and hard, so that the sternum appears to extend between 

 them (fig. 72). There are two tracheal openings just behind 



22 



Figs. 70, 71, 72. Dysdera 

 interrita. — 70, enlarged 

 four times. 71, head 

 and eyes from in front. 

 72, under side enlarged 

 six times. 



