110 



BRANCH ARTHROPODA 



(Sarcop'tes scab'ei) is the itch mite, causing the disease called the 

 itch. Still another is called the cheese-mite. 



Ticks (Ixo'des) are parasitic, blood-sucking Acarina which 

 attack man and other mammals. They do not exceed a centi- 

 meter in length, the males being the smaller. The so-called 

 " Texas fever " of cattle is transferred by the common cattle 

 tick (Fig. 81). 



Fig. 82. Horseshoe or king crab (slightly damaged on left). (From 



specimen.) 



Order IV. XIph'osu'ra. The Lim'ulus, or horseshoe crab (Fig. 

 82), is a marine arachnid living on the bottom of the sea in 

 shallow water, creeping along in the mud and sand and feeding 



