xi] THERAPHOSID SPIDERS 87 



noted that we often worked four or five hours a day 

 for a week in getting a fair idea of the habits of a 

 single species." 



CHAPTER XI 



THERAPHOSID SPIDERS 



IT is quite impossible in a work like the present 

 to deal with the classification of spiders. About 



forty families have been established, some of them of 



/ 



vast extent, the Attidae, for example, including some 

 four thousand species. The great French arachno- 

 logist, M. E. Simon, has occupied 2,000 quarto pages 

 in defining the families, sub-families and genera, 

 without concerning himself with the species at all ! 

 It is, however, desirable, that the attention of the 

 reader should be called to the primary division of 

 the group, according to which all spiders are either 

 Araneae verae (true spiders) or Araneae theraphosae 

 (theraphosid spiders.) 



Now these two kinds of spider may readily be 

 distinguished by a single easily observable charac- 

 teristic, the nature of the mandibles or chelicerae ; 

 but it is necessary to describe the spider's mandibles 

 before the difference can be appreciated. 



Their nature is perhaps best explained by saying 

 that each mandible is not unlike a penknife with 



