82 GASTROPODA. [Aspidobranchia. 



apex into fine granules. Colour bluish-white, usually buff around the 

 apex, striped in a divaricating pattern, or irregularly blotched and 

 rayed down the ribs with brown or olive. Apex not prominent, 

 at the anterior fourth or fifth. Interior bufnsh-olive, with a silvery 

 lustre, showing the colour-markings of the outside, having a white 

 or brown central callus, often ill denned. (Pilsbry.) 



Length, 44 mm. ; breadth, 34 mm. ; height. 8 mm. (typical 

 form). 



Dentition. Button, T.N.Z.I., xv, 129, pi. 16, f. E. 



Anatomy. J. A. Newell, T.N.Z.I., xix, 157, pi. 11. 



Hob. Throughout New Zealand, but more common on the east 

 coast of the North Island. 



Remark. This also is a very variable shell, especially in the colour- 

 pattern. 



Subsp. argenteus, Quoy and Gaimard, 1834. Plate 7, fig. 14. 



Patella argentea, Q. & G., Voy. Astro!., Zool., iii, 345, pi. 70, f. 16. 17. 

 Nacella argentea. Quoy : Huttoii, O.M.M., 45. Helcioniscus radians, 

 Gmel., subsp. argentea. Q. & G. : Suter, P. Mai. S., vi, 347. 



The shell has most of the characters of the species, but the interior 

 has no brownish radiate bands. The surface is sculptured by about 

 20 more or less elevated ribs, with several interstitial riblets. The 

 main ribs are light brown, sometimes punctured with white ; the 

 ground-colour is greenish or grey, often blotched with white ; the 

 nacre is silvery-white, frequently with a yellowish tint ; central area 

 greyish-white or cream colour, rusty in old examples. The shell is 

 generally much more elevated than the species. 



Length, 24 mm. ; breadth, 22-5 mm. ; height, 6-8 mm. (type). 

 Length, 50 mm. ; breadth, 41 mm. ; height, 21 mm. (specimen from 

 Surnner). Length, 42 mm. ; breadth, 34 mm. ; height, 15 mm. (speci- 

 men from Napier). Length, 53 mm. ; breadth, 44 mm. ; height, 17 mm. 

 (specimen from Timaru). 



Dentition the same as in the species. 



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



Hob. Throughout New Zealand ; most common on the east coast 

 of the South Island. 



Subsp. decorus, Philippi, 1848. Plate 7, fig. 15. 



Patella decora, Phil., Zeitschr. f. Malak., 1848, 162; Abbild.. pi. 3, f . 3 ; 

 Martens, Grit. List., 35. Helcioniscus radians, Gmel., subsp. decora, 

 Phil. : Suter, P. Mai. S., vi, 348. 



Shell mostly large, semiglobose. Apex much inclined to the an- 

 terior, more rounded than in the typical species, with 20-24 distant 

 reddish-brown ribs on a yellowish or greenish-olive ground. Interior 



