izo AMERICAN SPIDERS 



Our United States species are pygmies by comparison. A full- 

 grown male of Aphonopelma from Arkansas was found by W. J. 

 Baerg to weigh a little less than one-half ounce. The greatest total 

 length of the carapace and abdomen of this specimen was about two 

 inches. A representative female of the same species closely approxi- 

 mated the male in weight and body length. Large females often 

 weigh as much as two-thirds of an ounce after they have been well 

 fed. The long legs of our southwestern males span six or even 

 seven inches. 



Owing to their formidable appearance, the tarantulas have ac- 

 quired the reputation of being dangerous. This reputation they do 

 not live up to either in belligerence or in the virulence of their 

 bite. For the most part, they are sluggish creatures, which attack 

 only when goaded to an extreme. Although our species are credited 

 in many accounts with being great jumpers, leaping is not their 

 specialty, and they ordinarily strike over a distance of only a few 

 inches. In point of fact, they make fine pets, and some quickly 

 become so tame that they can be picked up and handled with ease. 

 The venom of most seems to have little harmful effect on man, but 

 the powerful chelicerae of large species are capable of producing 

 painful wounds. 



About thirty species of tarantulas live within the limits of the 

 United States, for the most part in the arid Southwest. Their ab- 

 sence from Florida and the southeastern states is rather surprising, 

 since that area is seemingly ideal for these hairy spiders. Their 

 eastern limit is the Mississippi River, and they occur north to a line 

 starting between Missouri and Arkansas and ending on the Pacific 

 Coast in the San Francisco region. 



Tarantulas abound in the tropics and there have developed many 

 interesting types. A few of them have become arboreal and move 

 over the surface of trees with great facility, frequently nesting in 

 bromeliads and other stations far above the ground. Even the 

 ground-loving species are good climbers, since their tarsi are pro- 

 vided with thick brushes of hairs, which enable them to climb a 

 vertical pane of glass with ease. The tarantulas of our American 

 Southwest (Plates 12 and 13; Plates XV, XVI and XVII) on the 

 other hand, are more restricted in habit. They are all ground loving, 

 and dig their own burrows or live in those abandoned by rodents. 

 Once they have become attached to a burrow and its particular 

 surroundings, they stay there during their whole life. The area in 

 which they hunt is small, usually only a few feet on each side, and 



