89 
DEFINITION OF A NEW SPECIES OF SOUTH 
AUSTRALIAN POLYPLACOPHORA. 
By M. M. MAUGHAN. 
[Read September 3, 1900.] 
Chiton bien sp. nov. Pl. i., figs. 3a—g. 
General Appearance .—Shape oblong, oval, very elevated, 
carinated, side eh steep and slightly curved. Shell sloping 
back from about valve five. Colour. —Greyish green, mottled 
with olive. Anterior valve slightly lighter in colour than the 
rest. Dorsal areas tipped with reddish tinge.  Girdle same 
colour as valves, with dark olive stripe opposite each lateral area, 
and at intervals round anterior and posterior va Mist 
Anterior Valve. —Steep, almost smooth, but showing scarcely 
lateral areas of other valves. Immediately in front of this area 
are = Sos wedge-shaped pits deseribed below.  Slits eight. 
n Valves.—Dorsal area beaked, merging into the pleural 
area, ‘faintly wrinkled with what appear to be growth lines. The 
marked feature of this shell i is the row of about 12 parallel, very 
areas are elevated with very low, Wat: longitudinal, faintly 
imbricating divisions. Slits 1.1. Insertion plates with pectinated 
Sinus broad, denticulated with 12 slits. A strong triangular rib, 
with apex at the posterior margin of the insertion pla ate, is seen 
inside of each of valves two to seven. Colour of articulamentum 
greenish white 
Girdle.—Scales smooth, wide, and very obtuse at apex. 
Measurement.—Length, 20 mm.; width, 10 mm. 
Habitat —McDonnell Bay ; : found by Dr. W. G. Torr, to 
whom I am indebted for specimens. 
EXPLANATION OF PLATE I. 
Dorsa l view of entire shell. 
alve. 
Anterior valve showing teeth. 
atn of girdle magnified. 
. Insertion plate, median valve. 
p easque pallens. 
jorge e Ro op 
n ru 
$ Chiton oruktus 
