194 PEOCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



18. AcANTHocHiTEs (LoBOPLAx) cosTATus, Adams & Angas. 



AcantJiochites costatus, Ad. & Ang. : Proc. Zool. Soc, 1864, p. 194 ; 



Angas, op. cit., 1867, p. 224. 

 Macandrellus costatus^ Ad. & Aug. : Dall, Proc. U.S. Nat. Mus , vol. i, 



p. 299, pi. iv, fig. 40 (dentition). 

 Chiton [Macandrellus) costatus, Ad. & Ang. : Smith, Zool. Coll. 



" Alert," p. 83, t. vi, fig. F. 

 Acanthocliites costatus, Ad. & Ang. : Pilsbiy, Man. Conch., ser. I, 



vol. XV, p. 40, pi. iii. fig. 74. 

 Tonicia ruhigmosa (Swainson), Hutton : Trans. New Zealand Inst., 



vol. iv (1872), p. 180; Man. New Zealand Moll., p. 114 ; 



Pilsbry, Man. Conch., ser. I, vol. xv, p. 107. 



On examining Hutton's type-specimen of Tonicia ruhif/inosa, which 

 is in the Colonial Museum, "Wellington, I found it to agree with the 

 description of A. costatus, and two specimens I have, which were 

 dredged in Foveaux Straits, also belong to the same species. The 

 specimen in the Colonial Museum has lost its colour entirely, but of 

 nay specimens one is yellowish-pink, and the other, a young shell, is 

 most beautifully ornamented with pink, white, light-brown, and 

 blue. The dimensions of Hutton's type- specimen are: length 11, 

 breadth 5 mm. 



Ilab. — The species has hitherto been found in Cook Strait and 

 Foveaux Strait. In tlio latter locality it is found with Chiton canali- 

 culatus. Very rare. 



CHITON, Linne, 1758. 



Key to Species. 



a. Central areas having longitudinal riblets. 



b. Sides and ridge of central areas both sculptured. 



e. Lateral areas with numerous slightly crenulatcd 

 threads. 

 d. Intermediate valves carinated, divergence 120°. Qnotii. 

 dd. Intermediate valves arched, divergence 100°. (evens, 



cr. Lateral areas with three or four rows of distinct tubercles, pellis-serpetitis. 

 bh. Central areas with a smooth baud or triangle on ridge of 

 each valve. 

 c. Lateral areas with 4-6, pleura 16 or more, granose 



riblets. canalicidatus. 



cc. Lateral areas with 2-4, pleura 8-14, nodulose riblets. 



d. Girdle-scales mucrouated. limans. 



dd. Girdle-scales not mucrouated. Stangeri. 



aa. Central areas smooth, no longitudinal I'ibs. Si>tclairi. 



19. CniTON QuoYi, Deshayes. 



Chiton viridis, Quoy & Gaim. : Voy. Astrolabe, Zool. vol. iii (1835), 

 p. 383, t. Ixxiv, figs. 23-8 (non Chiton viridis, Spongier). 



Chiton Quoyi, Deshayes in Lamarck, Anim. sans Vert., vol. vii(1836), 

 p. 509 ; Reeve, Conch. Icon., t. xiii, fig. 68 ; Hutton, 

 Trans. New Zealand Inst., vol. iv, p. 177; Pilsbry, 

 Man. Conch., ser. I, vol. xiv, p. 172, pi. xxxvii, figs. 6-8. 



