A Revision of the Genera of the Araneae. 51 



IX. — A Revision of (lie Genera of the ARANEiH or Spiders 

 with reference to their Type Species. By F. O. PiCKAHD 

 Cambridge, B.A. 



It might have been supposed that with Thorell's work on 

 the genera of European Spiders, in whicli the types have 

 been selected, written in 1869-70, and with Simon's splendid 

 volumes on the genera of the world, witli the types also 

 selected, appearing at intervals irom 1892 onwards, that 

 any revision would be unnecessary, and would simply mean 

 doing over again work already admirably accomplished. 



In the first place, it must be pointed out, however, that 

 neither of these two authors was apparently aware tliat the 

 types of twentj-.nine genera had been definitely selected by 

 Latreille in 1810. They are selected at the end of his work 

 ' Consid. g^n. Nat. Ord. Crust., Arachn. et Insectes,' in the 

 " Table des genres avec I'iiulicationde I'esj^co qui leur sert de 

 type." It is true that the types arc selected under the French 

 form of the generic name, but since both the Latin and French 

 forms are given in the earlier systematic part of the same 

 work, there cannot be the slightest doubt as to what is the 

 signification of the names and what {)articiihir group the 

 selected type represents. 



Thorell, too, allowed himself sometimes to be influenced 

 by wluit authors themselves would have wished with regard 

 to their jtublished names and species, forgetting that when 

 a name has once been publisiied it becomes public property 

 and the author has no further rights over it. He, for 

 instance, in the case of Micromata, Latreille, says that a 

 certain species, accentuata, " got in by mistake " and must 

 therefore be ignored. On those principles there is nothing 

 to prevent any author making the same assertion of any 

 species or any imrnber of them originally referred to any 

 genus. Uhorell, moreover, has in some cases been content 

 with deciding that such and such genera are synonyms of 

 others, and has therefore refrained t'rom selecting the tt/pes. 

 Since, however, genera dropped in haste are apt to be later 

 on restored at leisure, it is very im|)ortant to know what are 

 the type species which represent them, whether they are 

 eventually to stand or not. 



He does not, however, come to any conclusion without 

 giving his reasons very fully, and thus it becomes much 

 easier to revise his work and bring it up to date. 



The same remarks apply also to some extent to Simon's 

 work. He, too, set out apj>arently with some definite principles, 



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