598 



Bertkau, in a valuable treatise on the mandibles of Spiders '), has 

 endeavoured to make use of the differences in the structure of these 

 organs for systematization; the mandibles, as is well known, fre- 

 quently offer very good characteristics for the distinction of genera 

 and species , but for that of the higher groups this is but rarely the 

 case. Bertkau's attempt to group and characterize the families ac- 

 knowledged by him exclusively according to the structure of the 

 mandibles, appears to me therefore not to have led to any satisfac- 

 tory result: he has not, for example, been able to discover any di- 

 stinguishing differences in the mandibles of his LJrassides, Agelenides, 

 Thomirides and Lycosides , and when he, in order distinctly to se- 

 gregate at least the Thomisides from the other three families men- 

 tioned, proposes to refer Sparassus and Thanaius to his Lycosides, he 

 overlooks the fundamentally essential difference in the number and 

 structure of the tarsal claws, which separates Lycosoidcp, and Thomi- 

 soidce and at once renders such a transfer impossible. That Bertkau 

 in consequence of the structure of the mandibles is obliged to refer 

 Meta Meriance to the Theridides, cannot fail to suggest further objec- 

 tions against his attempt to make the structure of the mandibles an 

 essential distinctive mark of the families of spiders. 



In his important work, 'General list of the Spiders of Palestine 

 and Syria', Cambridge has given a systematic list of the families 

 and genera of the spiders met with in those countries. We find 

 from this, that he does not admit any 'Sub-orders', but at once di- 

 vides the spiders into a number of 'Families', which are however not 

 characterized in that work. The most important peculiarities of Cam- 

 bridge's system (as compared with the arrangement of spiders made 

 by me) appear to be, that he separates Palpi?nanus from Eresus 

 (fam. Eresoidce Thor.) and takes the first of these genera as the type 

 of a separate family, Palpimanides , whereas Eresus is united with 

 Dictyna, so as to compose the family Dictynides (I refer Dictyna to 

 the subfam. Amaurobiiim in the family Agalenoidce); moreover that 

 he refers to his Agelenides the genera E?iyo, Laehesis {Laches Thor.), 

 Storena and some others — among them Cydippe Cambr., or Gydrela, 

 as I propose to call it, the name Cydippe being preoccupied 2 ) — , 

 which I unite in a separate family, Emjoidce; and lastly, that the 



1) Ueber den Bau u. die Function der Oberkiefer bei den Spinnen etc., in 

 Archiv f. Naturgescb., XXXV, I, (1870). 



2) Cydippe [Ccelent.] Eschsch. 1829. — RvS^fjlo?, nom. prop. 



