395 
becomes curved and the pustules larger, more raised, and 
rounded. 
ab.— Victoria and South Australia. 
ACANTHOCHITON PILSBRYI MAUGHANEANUS, n. sp. 
Pl. xli., fig. 4. 
. Differs from A. pilsbryi, Sykes, in having pustules less 
raised and rounded. The pustules are even more rectangular 
than is the case in the dominant form; in the anterior valve 
r 
A. maughani as Sykes’ shell, that name becomes a synonym 
of A. pilshryi. I am therefore preserving the name of Mr. 
M. M. Maughan, the ex-Director of Education in this State, 
by naming the subspecies after him. 
ype I am presenting to the South Australian 
Museum; it was collected by myself at Middle Harbour, 
Sydney, New South Wales. ' 
Genus AcAxTHOCHITON, Gray, 1821. 
Subgen. NoTOoPLAX PORCINA, n. Sp. 
Pl. xli, figs. 7 to 10. 
_ General appearance.—Shell elongated, “glossy, carinated, 
side slope straight, all valves more or less covered with fine 
longitudinal ribbing. : 
olour and markings.—Light vinaceous-cinnamon, mot- 
tled with congo pink in the dorsal areas (Ridgway's Colour 
Standards, pl. xxviii. and xxix.). : 
. Anterior valve.—Has five shallow undulations or ray ribs, 
is fairly evenly covered with wavy, concentric ribbing; in 
oo these resemble “ripple marks” on the sea sand. 
