OF THE ANNULOSA. 349 



morphose, quih lie deviennent jamais des hisectes ailts ; 

 ainsi fttois comme assure que lesjeunes Tales devoieiit etre 

 semhlables en figure, a la grandeur pres a leur mere, et 

 pur consequence je croj/ois qu'ils etoient pourvus d'autant 

 de pattes qu'elle. Mais je vis toute autre chose: chacun 

 d'eux 71 avail en tout que six pattes qui composoient trois 

 paires, on dont ily avoit trois de chaque cole, da corps ; ils 

 avoient beaucoup de ressernhlance avec des vers ou larves 

 hexapodes, telles que celles qui doivent se transformer en in- 

 secles ailes." 



Four days after, Degeer discovered that his young luli 

 had gained four more pair of feet, that their antevinae 

 even instead of four articulations had now six, vvliile the 

 number of the annulose segments of which the body con- 

 sisted had been in an astonishing degree augmented. From 

 tlie knowledge of this singular fact we perceive the value 

 of our author's other observation on Porcellio previously 

 noticed ; we see in short that this genus, although truly 

 belonging to the class oi Crustacea, which, with the excep- 

 tion of some Branchiopoda, is generally characterized as 

 undergoing no change of form, has nevertheless a vestige 

 of the same extraordinary sort of metamorphosis which 

 takes place among the Chilognatha. 



The mouth properly so called of an lulus has no la- 

 brum, or at least has it represented by the emarginate 

 clypeus, and is shut immediately behind the mandibles 

 by a sort of crustaceous labium formed, according to Sa- 

 vigny, of two pairs of maxillae soldered together, and which 

 represent the four upper maxillae of decapod Crustacea. 

 The three first pair of feet answer by analogy, according 

 to the same author, to the three pair of auxiliary maxillse 

 or pedipalpi of these Decapoda. Those segments of the 



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