274 MANUAL OF NATURAL HISTORY. 



I. S HE-ORDER. QUADRIPULMONARY-SPIDERS 



(Tetrapneumona). 



Two pulmonary sacs and two spiracles on each 

 side ; legs robust. 



1. FAMILY. Bird-Spiders (Mygalidse). Eyes eight ; 



spinnerets four, two short and two promi- 

 nent ; hook or moveable claw of chelicerae 

 folded on the lower side, or that of the first 

 joint, moving vertically. 



2. FAMILY. Hunting-Spiders (Dysderid^e). Eyes 



six in many ; spinnerets six, very short ; 

 hook of chelicerse folded transversely or 

 along their inner side, moving laterally. 



II. SUB-ORDER. BIPULMONARY-SPIDERS 

 (Dipneumona). 



A single pulmonary sac and spiracle on each side 

 of abdomen. 



3. FAMILY True - Spiders (Araneidae). Hook of 



chelicerse folded transversely or along their 

 inner side, moving laterally. 



1. GROUP. Sedentary Spiders (Sedentaria). Eyes 

 arranged transversely on front of cephalo- 

 thorax ; throw out threads for the capture 

 of their prey, and station themselves upon 

 or near their webs. 



1. Tapestry -Weavers (Clubioninse). Spin- 

 nerets cylindrical, placed together and 

 directed backwards ; legs robust ; recti- 

 grade. 



