96 GASTROPODA. [Aspidobranchia. 



Subsp. Huttoni, Filhol, 1880. Plate 8, fig. 3. 



Haliotis Huttoni, Filh., " Comptes Rendus," xci, 1094 ; Filhol, Miss. I.C., 

 1885, 527. H. gibba, Pnil., var. Huttoni, Filh. : Hutton, P.L.S. N.S.W., 

 ix, 370. 



The spiral lirge are stronger and slightly waved, the apex is less 

 anterior, the shell more convex. The sculpture is much coarser, the 

 spiral lirse stouter and less numerous, strong and much finer cords 

 usually alternating. The colour is mostly light brown or greenish ; 

 there are no V-shaped streaks. As a rule, the shell is not so elongate 

 as the species. The prevailing colour of the interior is red. 



Length, 50 mm. ; breadth, 35 mm. ; convexity, 15 mm. Length, 

 52 mm. ; breadth, 38 mm. ; convexity, 18 mm. Length, 62 mm. ; 

 breadth, 43 mm. ; convexity, 21 mm. 



Type in the Mus. Hist, Nat., Paris. 



Hab. Campbell Island. 



Remarks. Captain Bollons told me that this mollusc is eaten by 

 the seals, apparently without crushing the shell with the teeth, and 

 when the animal has been digested the empty shells are disgorged. 

 The shells lying about on the beach are pearly outside, having lost the 

 epidermis through the action of the acid gastric juice in the stomach 

 of the seals. 



Fam. FISSURELLID.^, Risso. 



Animal bilaterally symmetrical externally, the anal orifice on the 

 median line either anterior, central, or posterior. Gills paired, one on 

 each side of the back, their free ends extending to the neck ; muzzle 

 stout ; eyes on peduncles of variable length at the outer bases of the 

 tentacles ; mantle continuous or slit anteriorly ; foot fleshy, bearing 

 generally a row of epipodial papillae. Adductor muscle horseshoe- 

 shaped, open anteriorly. Radula with central, lateral, and uncinal 

 teeth, the laterals usually 5 in number, narrow except the outer one, 

 which is very large, with a strongly recurved and denticulated cusp ; 

 uncini numerous. 



Shell conical, limpet-shaped, non-spiral (but with a spiral nucleus), 

 having a perforation, anterior slit, notch, or emargination for the 

 passage of the anus ; not nacrous ; having a horseshoe-shaped im- 

 pression of the adductor muscle ; bilaterally symmetrical. 



Carboniferous to Recent. 



Subfam. 1. FISSURELLIX.E. Pilsbry. 



Central tooth of radula narrow. Shell wholly external, capable 

 of containing the entire animal. Apex of shell wholly removed by the 

 anal perforation, which is bounded inside by a callus with entire 

 margins, not truncated or excavated posteriorly. 



This subfamily does not antedate the Pliocene. 



