8 SPIDERS [CH. 



But is it a spider ? 



Now some groups of the Arachnida may be put 

 out of court at once as having an appearance so 

 characteristic that no confusion is possible. Such 

 are the Scorpions, and the minute Chernetidea or 

 "False Scorpions," but this cannot be said of the 

 Phalangidea or " harvestmen " or of the Acarina or 

 " Mites," members of which groups not only may be, 

 but frequently are popularly taken for spiders. In 

 fact the Phalangidea are very commonly spoken of as 

 "harvest spiders' and the "red spider' is a mite. 

 A very brief inspection, however, with a pocket lens 

 will settle the matter without the least difficulty. 



A spider's body consists of two parts, a cephalo- 

 thorax (head + thorax) and an abdomen. There is a 

 waist, but no neck. The eight legs are attached to 

 the cephalo thorax, and the abdomen is not segmented 

 or ringed like that of an insect, but entire, and bears 

 at its extremity or on its under surface a little group 

 of spinnerets or finger-like projections from which the 

 spider's silk proceeds. For the moment these three 

 characteristics will suffice the "waist" behind the leg- 

 bearing portion of the body, the unsegmented, legless, 

 abdomen, and the spinnerets (fig. 1 B\ A harvest- 

 man, for instance, lacks the waist, and its abdomen is 

 segmented. Mites are of very varied form and in 

 some the body is more or less divided into two 

 portions, but at least two pairs of legs will be found 



