26 PROCKKDINGS OK THE MALACOLOGICAL SOCtETY. 



entirely due to tlie impetus given to collectors by Pilsbry's masterly 

 and most lucid treatment of tlie group. As stated above, Pilsbry's 

 luouograpli was entirely a coiu'hological one, and the few apparent 

 discrepancies were not easilj' corrected by the studj' of the shells alone. 



Dr. Thiele, in his llevision, through the co-ordinate study of the 

 radular characters, has remedied some of these inconsistencies; the 

 llevision is primarily constructed upon Pilsbry's monograph, and in 

 the majority of cases full value lias been given to conchological 

 features. There can be no hesitation in accepting Thiele's Revision 

 as a great advance upon the classification introduced by Pilsbry, 

 and I hope, through the study of large quantities of Australasian 

 material, to eifect some improvements upon Thiele's Revision. My 

 criticism of Thiele's Revision has been mainly conchological, so that 

 it is most pleasing to find that we are so much in accord. In the 

 succeeding pages I propose several amendments, and it is well to 

 state that these proceed from the study of much Australasian material 

 in conjunction with my Kermadec specimens. My earlier notes in 

 these Proceedings concerning Australasian Chitons dealt mainly with 

 the identification and nomination of species. In this paper I give 

 more attention to the higher groupings, but also take the opportunity 

 of correcting some errors occurring in those notes. 



As Dr. Thiele's Ptevisiou may not be generally available to readers 

 of these Proceedings, I would note here the groupings referring to the 

 Kermadec Chitons thus : — 



Sub-order. Familij. 



Lepidopleuiin.i. Lepidopleuridoe. 

 'Callochitonidje. 

 ^Iopaliida3. 

 ('hitonina. ^ Crypto})lacidfe. 



Ischnochitonida). 

 lChitonida3. 



1 have not altered any of these family groupings, but give reasons for 

 differing from both Thiele and Pilsbrj' as regards the genera utilized, 

 and 1 am still continuing my researches in this direction. The notes 

 given in quotation marks after the station of the species are extracts 

 from my paper in this journal above noted, and are here introduced 

 so that correlation with the previously unnamed species can be made. 



Order POLYPLACOPHORA. 



Sub-order LEPIDOPLEURINA. 



Family LEPIDOPLEUKID^. 



Genus Parachixon. 



Parachiton, Thiele: Chun's Zoologica, Heft Ivi (Revision des Systems 

 der Chitonen), pt. i, p. 14, 1909. 



Type (by monotypy) : Lepidopleuriis acuminatum, Thiele. 



At the place quoted Thiele described Lepidopleurus acwninatus from 

 Duke of York Island. He introduced Parachiton as a sub-generic 

 luune to be used on account of certain peculiar features, one of which 



