394 
DESCRIPTIONS OF SIX NEW SPECIES OF AUSTRALIAN 
POLYPLACOPHORA (FOUR ACANTHOCHITONS AND TWO 
CALLISTOCHITONS), WITH OTHER NOTES. 
By Epwin Asus, F.L.S., M.B.O.U. 
[Read October 9, 1919.] 
Pirates XLI. anp XLII. 
ACANTHOCHITON PILSBRYI, Sykes. 
Pies, Gps. i63 
A. pilsbryi, Sykes: Proc. Mal. Soc., vol. ii., pt. 2, July, 1896. 
. maughani, Torr and Ashby: Trans. Roy. Soc. S. Austr., 
vol. xxii., 1898. > - 
I am indebted to Mr. James A, Kershaw, of the National 
Museum, Melbourne, for the opportunity of examining Sykes' 
type of the above shell. Sykes states that he had only the 
single specimen and did not disarticulate the anterior valve. 
An examination of the type at once gives the reason, for that 
valve, in common with several of the others, is badly broken. 
Further, the marked character of the sculpture of this shell 1s 
much obscured in the type owing to erosion and fracturing, but 
still more to the extensive limy encrustations, the deep inter- 
spaces between the pustules being in most cases entirely filled 
in with the accretions. 
The very faulty drawings and description in Sykes' paper 
are undoubtedly due to this feature. Both Mr. Sykes and 
Dr. Pilsbry, to whom he submitted the type, emphasize the 
character of the dorsal area, ! 
4. pilsbryi, method of 
sculpture in pleural area. 
e 
e 
ridging connects the pustules of one row 
next row. In the lateral area the row 
