GASTEROPODA. 49 



valves generally green, inclining, more or less, to yellowish on the back, 

 with the waved strife brown ; sometimes the valves are greyish green, 

 with many of the undulating strise white. Length, 1*15 ; breadth, 55. 

 Not uncommon under stones at low water. Chatham Islands. 



229. T. rubiginosa, Hittton, Trans. N.Z. Inst., \v.,p. ISO. Ob- 

 long ; margin slightly tomentose ; valves rather elevated, sub-carinate, 

 flattened on each side ; posterior margins straight, produced into an 

 acute central point ; lateral areas indistinct, the whole surface rather 

 coarsely granular, the granules smaller on the back. Pink, getting 

 yellowish on the back. Length, - 45 ; breadth, '2. 



ACANTHOPLEURA. 



Mantle covered with long spines, widely spread. 



230. A. ciliata, Reeve; A. complexa, Hutton, Trans. N.Z. Inst., 

 iv., p. 181. Oval ; margin broad, velvety, with long spines scattered 

 over it ; valves depressed, flattened on each side, sub-carinate ; pos- 

 terior margins not covering the next at the corners, rather convex, and 

 pointed in the centre ; anterior valve with radiating moniliform ridges ; 

 lateral areas of intermediate plates granulose, with two prominent, 

 radiating, slightly curved ridges on each side ; median areas with finely 

 granular transverse waved lines, which pass imperceptibly into the 

 larger lateral granulations ; posterior valve small, like the intermediate 

 ones ; centres of valves punctate internally. Margin reddish brown, 

 varied with darker ; valves greyish, more or less varied with yellowish 

 white, yellow, or brown. Length, 1 ; breadth, '5. 



Pitt's Island. 



231. A. CSBlatUS, Reeve ; Tonicia zig-zag, Hutton, Trans. N.Z. 

 Inst., iv.,p. 180. Oblong; mantle slightly tomentose; valves slightly 

 flattened on each side, but not keeled ; posterior margins sloping 

 backwards into a point, creuulated on the sides ; anterior valve with 

 nine radiating ridges, crossed by fine concentric zig-zag stria} ; lateral 

 areas with two, on each side, radiating ridges crossed by fine zig-zag 

 strise ; posterior and median areas with very fine oblique strise diverg- 

 ing from the dorsal line outwards and forwards, crossed by others 

 diverging outwards and backwards, forming an " engine-turned " 

 pattern. Mantle white ; valves greyish black, with a white stripe on 

 each side of the dorsal line ; interior greenish blue. Length, - 88 ; 

 breadth, '31. 



Not uncommon in the South. 



232. A. nobilis, Gray, Dieff. N.Z., ii., p. 245. Mantle rugose, 

 rough, with scattered long tapering brown bristles ; valves brown, con- 

 vex, evenly rounded, with very minute dots like shagreen, the lateral 

 area slightly marked with three or four indistinct rays ; inside white. 

 Length, 3. (Gray.) 



I have only seen a single valve. 



ACANTHOCHJETES. 



Margin of the mantle spinulose, with nine bundle- .s of spines along 

 each side. 



Australia. Europe. 



7 



