Mem. Nat. Mus. Vict. vm. 1934. 
THE GIRDLE SCALES OF 1SCRNOOHITON 
( CHARTOPLAX ) PUR A Sykes. 
By John S. Mackay, M.D., Hon. Conchologist ( Loricates ). 
Plate XVII. 
Family ISCHNOCHITONIDAE Dali 1889. 
Genus ISCHNOCHITON Gray 1847. 
Subgenus Chartoplax Iredale and Hull 1924. 
I schnochiton ( Chartoplax ) pur a Sykes. 
1890. / schnochiton ( Haploplax ) pura Sykes, Proc. Mai. Soc., ii, 1890 88 
pi. vi, fig. 3, 3a. 
1924. Haploplax ( Chartoplax ) pura (Sykes). Iredale and Hull, Aust. 
Zool., iii, 1924, 295. 
I schnochiton ( Chartoplax ) pura is a rare shell. Nine speci- 
mens are known to the writer. Of these, three are in the 
Bracebridge Wilson Collection, National Museum, Melbourne ; 
they include the type and two paratypes. There is one specimen 
in the collection of Mr. J. H. Gatliff. Mr. C. J. Gabriel had two 
specimens, one of which he generously gave to the writer. Mr. 
Edwin Ashby has two examples which he courteously sent to 
the writer for examination. These eight specimens were dredged 
from approximately the same locality in 6-10 fathoms near 
Portsea, Port Phillip, Victoria. Mr. A. F. Basset Hull has one 
specimen dredged in 12 fathoms at Disaster Bay, N.S.W. He 
very kindly forwarded it for examination and comparison. 
Sykes described the shell in 1896 (supra). The general 
features were those of genus / schnochiton , but, as the shell was 
almost lacking in sculpture and the girdle scales appeared to be 
' very small and smooth,” Sykes thought it might be included 
in the subgenus Haploplax. 
Iredale and Hull, basing their description on Hull’s specimen 
from Disaster Bay, wrote ‘‘Girdle wide, scales small, elongate, 
smooth, flattened, closely imbricating” (Monograph of the Aust. 
Loricates, p. 40). They left it in genus Haploplax on account 
of its smooth shell and extreme rarity, but suggested the sub- 
generic name of Chartoplax, ‘‘the smooth scales being in form 
quite unlike those of any other member of the genus.” 
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