152 Edwin Ashby : 



Plaxiphora albida, Blainville, syn. pctholata, G. B. Sby., and so 

 identified by Sykes. 



Acanthochiton bednalli, Pilsbry. One specimen only, correctly 

 identified by Sykes. 



Acanthochiton pilsbryi, Sykes. Type. After careful cleaning 

 this type specimen was found by the writer to be conspecific with 

 A. maughani, Torr and Ashby* and fully described by him in 

 Trans. Roy. Soc. of S. Aust., vol. xliii., 1919. 



Acanthochiton gatliffi, Ashby. This specimen was marked (?) 

 A. bednalli. A second specimen is in the collection (9G.P.B.) mis- 

 identified by Sykes as A. bednalli. I have placed this in a separate 

 capsule. Of these two specimens one is in fair condition, the 

 other eroded. It is remarkable that these specimens have for 

 so many years been in this collection, and yet no worker has 

 noticed their distinguishing characters. I only' described this 

 species last year from a specimen collected by myself at Port 

 Lincoln, South Australia. 



Acanthochiton {Notoplax) matthewsi, Bed. and Pils. Iden- 

 tified as such by Sykes. 



Acanthochiton {Notoplax) speciosus, H. Adams. Identified 

 as such by Sykes. 



Acanthichiton wilsoni, Sykes. Type. Afterwards described by 

 Dr. Torr under the name of levis. which becomes a synonym. 

 This is a very fine species. The little, somewhat eroded specimen 

 numbered 909 is, I think, referable to this species, but no men- 

 tion is made of it in Sykes' paper. 



Acanthochiton {Notoplax) glyptus, Sykes. Type. This is in 

 some respects, I think, the finest of all our Australian Acantho- 

 chitons. As far as I am aware, only three specimens have been 

 taken since Sykes' description was written, all three being taken 

 by Mr. Gatliff in Victoria. 



Cryptoplax striutus, Lamark. So identified by Sykes. 



Rhyssoplax bednalli, Pilsbry. Identified as such by Sykes. 

 This fine Chiton is still exceedingly rare. I have only taken a 

 single valve myself, and I believe all the very limited shells 

 known have been dredged. The sculpture coincides so closely 

 with R. exoptandus as to suggest that it is a deep water form of 

 that species. 



Rhyssoplax tricostalis, Pilsbry. Wrongly identified by Sykes 

 as the New South Wales shell, which had been described by A. 

 Adams under the name of Chiton muricatus, a name which Sykes 

 points out in his paper was pre-occupied, and he adopts Carpen- 



