IIo CHITONID. 
P. stella, Zesson; Voy. Coguille, Zool., ii., p. 421. Solid, small, 
depressed, irregularly oval ; apex sub-central, sharp, with seven radiating 
angular ribs, rounded above, thick, separated by wide depressions ; 
these ribs are divergent, and number four in front and three behind. 
In the middle of each pair there is a smaller rib, and two on the sides 
in the interval which separates the four anterior from the three posterior. 
Shell greenish above, spotted with black in double interrupted circles ; 
the border is stellate, with seven angles, having teeth in the intervals ; 
the interior face is slightly hollowed, thick and granular in front ; bluish- 
white ; apex white, dotted with maroon (Lesson.) 
Length, ro lines ; breadth, 9 lines ; height, 3 lines. 
P. earlii, Reeve, Conch.; Ic, f- 71. Shell rotundately ovate, 
slightly attenuated in front, convexly raised; apex inclined anteriorly, 
radiately ridged ; ridges small, very few and distant, with the interstices 
irregularly elevately striated; pale green, broadly wave-variegated with 
olive-black ; interior transparently iridescent ; milk-white in the middle 
(Reeve.) 
P. flexuosa, Hutton, C.M.M., ~. 45.  Ovate, depressed, not 
ribbed, but with fine concentric striz ; margin entire; pale yellowish, 
with deeply waved concentric brown lines ; interior silvery. 
Height, 6; length, 1°7 ; breadth, 1-4. 
Stonyhurst. 
Perhaps a variety of the last. 
P. rubiginosa, Hutton, CMM, p. 42. Conical, ovate ; apex 
sub-anterior, thin, smooth, radiately ribbed; ribs thirteen to seventeen ; 
outside white ; interior pinkish. 
Height, ‘2; length, ‘6; breadth, ‘5s. 
Auckland to Bank’s Peninsula. Chatham Islands. Auckland 
Islands. 
DIVISION—POLYPLACOPHORA. 
Gills in two lamellar series, one on each side of the hinder part of the 
body under the mantle edge. Valves eight, forming a linear imbricate 
series on the middle of the back. Radula long, linear ; central series 
with many teeth, middle one unlike the rest, outer lateral one on each 
side, very large, with a black opaque hook; lateral teeth several, forming 
jointed unarmed lamella; one erect, hooked (4-6.2.1.2.4-6. ;) monceci- 
ous ; anus posterior, median. 
FAMILY—CHITONID:. 
Head surrounded by a semi-circular veil or hood; eyes and tenta- 
cles none; mouth with cartilaginous jaws. Gills in a series of lamellz 
between the mantle and the foot. Foot oblong, rounded at each end. 
Shell of eight imbricated valves or plates, immersed in the coriaceous 
mantle, which forms an expanded margin beyond them. 
Sub-Family— Chitonine. 
Mantle simple, without any pores or tufts of spines on the sides. 
