192 niOCEEDIiNOS OF THE MALACOLOGICAL SOCIETY. 



12. Plaxiphora (Guildingia) obtecta, Pilsbry. 



riaxlphora ohtcda (Cpr.), Pilsbry : Man. Concli., ser. I, vol. xiv 

 (1893), p. 330. 

 I have not seen this very interesting species, which is not in any of 

 onr Musenms. 



13, Plaxiphoka (Fkemblya) ovata (Hutton). 



AcanthochMes ovatus, Hntton : Trans. New Zealand Inst., vol. iv, 



p. 182 (1872). 

 Acnnthochites ovatus, Hutton: Man New Zealand Moll., p. 117. 

 Plaxiphora ovata, Hutton : Pilsbrv, Man. Conch., ser. I, vol. xiv, 

 p. 332, pi. liv, figs. 34-40. 

 Rah. — This handsome but rare mollusc is found mostly in roots of 

 DurviUcca. Type in the Colonial Museum, Wellington. 



SPONGIOCHITON, Carpenter, 1873. 



14. SpoNGiocniTON PKODucTus, Pilsbry. 



Spongiovliiton productus (Cpr. MS.), Pilsbry : Man. Conch., ser. I, 

 vol. xiv (1892), p. 26. 



I have not seen this species. 



ACANTHOCHITES, Eisso, 1826. 



Key to Species. 



a. Anterior valve without radiating ribs; not obviou.sly lobed around 

 the lower edge of tegmeutum. 

 h. Tail valve with one slit on each side ; girdle covered with 



spicules and having well-developed tufts. Zclamlivns. 



bb. Tail valve with several slits ; girdle naked, leather\-, covering 

 the valves except for a linear baud at the ridge ; small 

 tufts on tubercles. poiostis. 



(1(1. Anterior valve having five radiating ribs, its lower margin 5 -lobed. 

 Girdle with eighteen small pore tufts. 

 b. Girdle leathery, naked, except tufts. vlolaccus. 



bb. Girdle covered with white spicules, especially at the margin. costatus. 



15. AcANTnocHiTES Zelandicus (Quoy & Gaimard). 



Chiton Zelandicus, Quoy & Gaim. : Voy. Astrolabe, Zool. vol. iii 



(1835), p. 4U0, t. Ixxiii, figs. 5-8; Peeve, Conch. Icon., 



t. xi, fig. 58. 

 Acanfhochites Zealandicus, Quoy & Gaim. : Hutton, Man. New Zealand 



Moll., p. 117. 

 Acanthochites Zelandicus, Quoy & Gaim. : Pilsbry, Man. Conch., ser. I, 



vol. XV, p. 16, pi. xiv, figs. 9, 10. 

 Aeantliochcetes Hookeri, Grav : Dieffenbach's "Travels in New 



Zealand," vol. ii (1843), p. 262; Hutton, Trans. New 



Zealand Inst., vol. iv, p. 182. 



