234 



SYSTEMATIC ZOOLOGY. 



jaws are strong, and venomous enough to kill the insects 

 upon which these animals feed; but the alleged cases of 

 serious or fatal poisoning of man as the result of spider- 

 bites need authentication. 



ORDER III. PHALANGIDA. 



This name is given to the animals familiarly known 

 as 'harvestmen' and 'daddy-longlegs/ with small bodies 

 in which there is no waist between thorax and abdomen, 



FIG. 62. Harvestman (Phalangium picturn). 



and with extremely long legs. These forms feed upon 

 small insects, but are perfectly harmless to larger animals. 



ORDER IV. ACARINA. 



Here belong the mites, in which the unsegmented abdo- 

 men is fused to the cephalothorax, and 

 in which the first two pairs of appendages 

 are modified into a piercing-organ. By 

 means of this structure, the ticks burrow 

 into the skin of cattle or of man, the itch- 

 mite makes its way into the thin skin 

 between the fingers, and the red mite 

 sucks the juices of plants. As a rule the 

 Acarina are parasites, and hence the group 

 is largely made up of pests. 



FIG. 63. Cheese- 

 mite, enlarged. 



