THE NAUTILUS. 
55 
where they denticulate the sutures. Rarely a fourth very short rib 
is indicated on some valves. Central areas having a smooth dorsal 
band of about the same width in front and behind, or somewhat 
wider in front. Pleura having 14-15 longitudinal riblets, narrower 
than their intervals, the inner 1 to 3 on each side not reaching to 
the anterior margin of the valve. Head valve with 17-19 radiating 
tuberculate ribs. Posterior valve elevated, the mucro projecting, 
posterior slope concave. Interior milky bluish, the sutural laminse 
white. 
Girdle densely clothed with imbricating finely striated scales, 
shaped like those of Chiton Sinclair i and measuring about one-third 
of a millim. in width. 
Length 17, breadth 9 mill.; an olivaceous, variegated specimen 
is somewhat larger. 
Hub. St. Vincent Gulf, S. Australia (W. T. Bednall). 
This form differs from C. muricatus in the shape of the girdle 
scales. It is more roughly sculptured than C. canaliculatns, with 
the girdle-scales different in form, although they are about the same 
width ; and with a different pattern of coloring, although in this 
respect all the allied forms of the canaliculatus group vary a good 
deal. The smooth dorsal band is wider than in canaliculatus. 
It is somewhat doubtful whether this should be considered a geo¬ 
graphic variety of the New Zealand species or an independent 
species. It is at all events closely allied to the C. canaliculatus, 
although actual connecting links between the two are unknown to 
me. The detail figures given in volume xiv of the Manual of Con- 
chology (pi. 36, f. 4, 6) excellently represent the sculpture of C. 
canaliculatus, being drawn from a specimen furnished by Professor 
Hutton. 
Chiton aereus var. calliozona n. var. 
Shell oblong, elevated, the dorsal ridge acutely keeled, side-slopes 
straight; light olive-green, with a few concentric lighter streaks 
upon each valve, and obscure dusky-green longitudinal streaks on 
each side of valves ii and vi, less conspicuous on iii and v. Poste¬ 
rior (sutural) margin of valves i to vii articulated or tessellated, 
being painted with alternate white and brown oblique spots. Girdle 
buff, paler on the outer half of its width, variegated with transverse 
bars of crimson and black scales mingled with the buff ones; about 10 
bars on each side. 
