THE SPIDERS. l8l 



possessing several pairs of feelers like legs, of a thorax, to 

 the three rings of which are attached three pairs of legs, 

 and of a hinder, body, or abdomen, consisting of many dis- 

 tinct rings. In the articulation of their body, the Solifugtie 

 are therefore in reality more closely related to flies than 

 to other spiders. Out of the Devonian Primteval Spiders, 

 which were nearly related to the Solifugae of the present 

 day, the Long Spiders, the Tailor Spiders, and the Round 

 Spiders probably developed as three diverging branches. 



The Long Spiders (Arthrogastres), in which the earlier 

 articulation of body has been better preserved than in Round 

 Spiders, appear to be the older and more original forms. 

 The most important members of this sub-class are the scor- 

 pions, which are connected with the Solifugae through the 

 Tarantella (or Phrynidse). The small book scorpions, 

 which inhabit our libraries and herbariums, appear as a de- 

 generate lateral branch from the true scorpions. Mid-way 

 between the Scorpions and Round Spiders are the long- 

 legged Tailor-spiders (Opiliones) which have possibly arisen 

 out of a special branch of the Solifugae. The Pycnogonida, 

 or No-body Crabs, and the Arctisca, or Bear Worms — still 

 generally included among Long Spiders — must be completely 

 excluded from the class of Spiders ; the former belong to the 

 Crustacea, the latter to Ringed worms. 



Fossil remains of Long Spiders are found in the Coal. 

 The second sub-class of the Arachnida, the Round Spiders 

 (Sphserogastres), first appear in the fossil state in the Jura, 

 that is, at a very much later period. They have developed 

 out of a branch of the Sohfuga, by the rings of the body 

 becoming more and more united with one another. In the 

 true Spinning Spiders (Aranese), which we admire on 



