62 Transactions. — Zoology. 



P. ovata, Hntton. 



Man. N.Z. Moll., p. 117. 



Genus Spongiochiton, Carpenter (1873). 



S. prodiichis (Cpr.), Pilsbry. 



Pilsbry, Man. Conch, (i), vol. xiv., p. 26. 



Genus Acanthochites, Risso (1826). 

 Key to Species. 



A. Anterior valve without raHiating ribs ; not obviously 

 lobed around the lower edge of tegmentum. 

 B. Tail valve with one slit on each side ; girdle 

 covered with spicules, and having well- 

 developed tufts .. .. .. .. A. zelandicus. 



BB. Tail valve with several slits; girdle naked, 

 leathery, covering the valves except for a 

 linear band at the ridge ; small tufts on 

 tubercles .. .. •• •• A. porosus. 



AA. Anterior valve having 5 radiating ribs, its lower 

 margin 5 lobed. Girdle with 18 small pore-tufts. 

 B. Girdle leathpry, naked except tufis .. .. A. violaceus. 



BB. Girdle covered with white spicules, especially 



at the margin .. .. .. .. A. rubigmosus. 



A. zelandicus, Quov and Gaimard. 

 Man. N.Z. Moll., p. 117. 

 Hookeri, Gray, is a synonym. 



il. ^orosws, Burrow. 



Man. N.Z. Moll., p. lis. 



Leachi, Blainville ; vwnticularis , Q. and G.; zelandicus, 

 Gray ; (?) depressns, Blaine ; (?) steivartianus, Eocheb., are 

 synonyms. 

 A. violaceiis, Quoy and Gaimard. 



Man. N.Z. Moll., pp. 117, 118. 



Porphyreticus, Eeeve, is a synonym. 



A. ruhiginosus, Hutton. 



Man. N.Z. Moll., p. 114. 



Costatus, Suter (not of Ad. and Ang.), is a synonym. 



Genus Chiton, Linne (1758). 



Key to Species. 



A. Central areas having longitudinal nblets. 



B. Sides and ridge of central areas both 

 sculptural. 

 C. Lateral areas with numerous slightly 

 crenulated threads. 

 D. Intel mtdiate valves carinated, di- 

 vergence 120° . . . . . . C. quoyi. 



CO. Lateral areas with b or 4 rows of dis- 

 tinct tubercles .. .. .. C . pellis-serpeniis. 



BB. Central areas with a smooth band or triangle 

 on ridge of each valve. 



