90 PROCEEDINGS OF THE MAL.4C0L0GICAL SOCIETT. 



Chiton {Lophyrus) higuhris, Gould : Proc. Bost. Soc. Nat. Hist., 

 vol. vii, 1859, p. 163; Otia Conch., p. 116; Pilsbiy, 

 Man. Conch., ser. I, vol. xiv, p. 146. 



Several specimens. I have followed Mr. Pilsbry ' in the above 

 synonymy, and am able to confirm it in regard to C. metallictcs, Reeve, 

 as I have examined the types, 



13. Plaxiphoka petholata (Sowerby). 



Chiton petholatus, Sow.: Mag. Nat. Hist., n.s., vol. iv, 1840, p. 289; 



Conch. Illust., figs. 64, 65, and var. porphyrim, fig. 59 ; 



Reeve, Conch. Icon., pi. xiv, fig. 74. 

 Plaxiphora petholata, Sow. : Pilsbry, Man. Conch., ser. I, vol. xiv, 



p. 323, pi. Ixviii, figs. 62-7 ; Proc. Acad. Nat. Sci. Philad. 



1894, p. 74. 

 Clmtopleura conspersa, Ad. and Ang. : Proc. Zool. Soc. 1864, p. 193. 

 Chiton (^Plaxiphora) terminalis, Cptr. : Smith, Voy. "Erebus" and 



"Terror," Moll., p. 4, pi. i, fig. 13. 

 ? Tonicia zigzay, Hutton : Trans. N.Z. Inst., vol. iv, p. 181. 

 ? Chiton coelatus, Reeve: Conch. Icon., pi. xvii, fig. 101. 

 Euplaciphora modesta, Cptr. : Haddon, Rep. "Challenger," pp. 33, 34. 



The species of Plaxiphora, as Mr. Pilsbry states in the "Manual," 

 are in great need of revision, and it is now very difiicult to identify 

 specimens with certainty. It is qiiite possible that two of Rlainville's 

 species, Chiton costatus and Chiton raripilosus, may be identical 

 with P. petholata ; but this will probably never be clearly settled, 

 Chcetopleura conspersa, Ad. and Ang., is, in my opinion, only a more 

 strongly sculptured form of P. petholata, thus showing a link towards 

 P. tenninalis, which latter was described from New Zealand. In 

 placing P. terminalis in the synonymy, I am guided by an examina- 

 tion of the type specimens, which appear to ditfer only in being more 

 strongly sculptured, and in the valves being a little narrower and 

 longer in proportion. Mr. E. A. Smith permits me to state that he 

 agrees in this opinion. It should be noted that in C. conspersa the 

 valves are even more strongly sculptured than in P. terminalis. 

 There is no doubt as to the correctness of placing PJ. modesta as 

 a synonym. AVhat the Tonicia zigzag of Hutton is, only an examina- 

 tion of the type specimen can settle satisfactorily : he placed it as 

 a synonym of Chiton coelatus, Reeve. There do not appear to be 

 any specimens in the Cuming Collection much resembling Reeve's 

 figure ; and the, presumably type, tablet bearing this name, appears 

 to me only to contain a form of P. petholata. The Btrcptochiton 

 ciipreus, Cptr. MS., appears to be a distinct species. There is a quaint 

 slip in the " Manual," ^ where the dimensions of T. zigzag are given as 

 "Length 88 inch.; breadth 31 inch." This would indeed be a fine 

 species ! 



^ l\[an. Conch., ser. I, vol. xiv, p. 144 ; xv, p. S7. 

 2 Vol. xiv, p. 329. 



