ARACHNIDA : SPIDERS. 



343 



trapneumones. They inhabit warm countries, and live in 

 cylindrical holes. The celebrated " Trap-door Spider " 

 is of this division. To their holes or tubes they construct, 



FIG. 467. 



Large Hairy Spider, Mygale Hentzii: Missouri and southward. 



of silk and earth, a perfectly fitting lid or door, hanging 

 the door with a hinge of silk ! 



A vast majority of spiders have only two lung-sacs, and 

 hence are called Dipneumones. These have three pairs 



