422 Transactions. 



many dissected examples, but it obviates puzzles such as presented by the 

 record of the species P. glauca Q. & G. from the Chatham Islands. The 

 item in Suter's description, " Posterior valve convex, with transverse lines, 

 mucro terminal," suggests its reference to the subgenus Maorichiton, and 

 consequently its identity with Thiele's P. schauinslandi. The terminal 

 mucro is characteristic of the subgenus, the mucro in Australian shells 

 being never terminal, but subterminal or subcentral. 



Genus Acanthochiton (Gray, 1821, em.)- [P- 25.] 



The introduction of the subgeneric name Acanthochitona by Gray in 

 the " London Medical Eepository," vol. xv, p. 234, 1821, has been con- 

 stantly overlooked, the later Acanthochiles of Risso, 1826, being commonly 

 in use. When I restored it (Proc. Mai. Soc. (Lond.), vol. xi, p. 126, 1914) 

 I also gave notes on the names Amicula, Cryptoconchus, and Macandrellus, 

 and advocated the recognition of four generic types in the Acanthochitons 

 of New Zealand. The synonymy of these names has been discussed in 

 detail at the place quoted, so need not here be elaborated. The family 

 name should be Cryptoconchidae. as I noted that Cryptoconchus must be 

 regarded as introduced in 1815, and therefore antedates Acanthochiton 

 Gray, 1821. I agree with Suter (p. 1080) that Spongiochiton productus 

 Pilsbry should be dismissed from the New Zealand list. 



Amaurochiton glaucus (Gray, 1828). [P. 34.] 



In the " Spicilegia Zoologica," pt. 1, p. 5, 1828, Gray described Chiton 

 glaucus from unknown locality. Pilsbry rejected this name, as he con- 

 sidered the description inadequate, and stated that the type was lost. It 

 appears he wrote this last sentence without inquiry, as the type is pre- 

 served in the British Museum. Further, Pilsbry based his monograph upon 

 Carpenter's manuscript notes, and Carpenter recognized the type, and 

 upon the back of the tablet is a note by Carpenter regarding his identi- 

 fication. It is undoubtedly the New Zealand shell, and all Neozelanic 

 specimens for many yeais were, and are still, given Gray's specific name. 

 I simply noted this fact in the Proc. Mai. Soc. (Lond.). vol. xi, p. 38, 1914, 

 in a footnote, when noting the dissimilarity between " Chiton pellisserpentis 

 Quoy and Gaimard " and "Chiton quoyi Deshayes " = Amaurochiton 

 glaucus (Gray). The usage of the generic Amaurochiton becomes necessary 

 through the rejection of " Chiton " as applicable to a heterogeneous as- 

 semblage of Chitons with scaly girdles and pectinated insertion teeth. 



Amaurochiton was proposed by Thiele from an examination of the radular 

 characters of Chitons. The name was given to the South American species 

 C. olivaceus Deshayes. Thiele also proposed Triboplax generic-ally for the 

 present species, but these are only specifically distinct. Indeed, sonic 

 workers have used the names as if they were conspecific. The relation- 

 ship is really very close, and there can be no hesitation in using the above 

 generic name. Chiton belongs to a species which superficially recalls Chiton 

 pellisserpentis Q. & G., and the rejection of it in the present connection 

 will be admitted as necessary by every accurate worker. 



Craspedochiton cuneatus (Suter). [P. 42.] 



The genus Tonicia must be dismissed from the Neozelanic fauna, and 

 the species named by Suter Tonicia cuneata transferred to Craspedochiton. 

 On p. 1081 Suter records Thiele's conclusion to the same effect from study 



