262 



ZOOLOGY 



distinct abdominal segments, 

 as the older fossils distinctly 

 show. A very few Asiatic 

 species still have this character 

 fairly well developed, at least 

 on the upper surface. 



The mites, though mostly 

 very small, include the ticks, 

 some of which are as large as 

 peas, or even larger. Although 

 the arachnids have nearly al- 

 ways four pairs of legs, whereby 

 they differ at once from the in- 

 sects, which have only three, 



FIG. 75. A scorpion (natural size). .1 n , i .1 i 



the gall mites have the legs re- 

 duced to two pairs. The simple eyes (usually eight) 

 of the spiders contrast with the large compound eyes of 



FIG. 76. A wolf spider. 



