20 THE VOYAGE OF H.MS. CHALLENGER. 



Callistochiton, Carpenter. 



Callistochiton antiquus (Reeve). 



Cliiton antiquus, Reeve, Conch. Icon., 1847, pL xxv. fig. 169. 

 Lepidopleurus antiquus, Angas, Proc. Zool. Soc. Lond., 1867, p. 223. 

 Callistochiton antiquus, Carpenter MS. 



Habitat. — Port Jackson. 6 to 1 5 fathoms. 



Port Jackson and Newcastle, New South Wales (Dr Dieffenbach in British Museum). 



This species closely resembles Callistochiton elenensis, Sow. (Proc. Zool. Soc. Lond., 

 1832, p. 27, and Conch. Ulust., No. 79, pi. clxii. fig. 69), from St Elena, West Colum- 

 bia, and Panama. Angas considers them synonymous, but he retains Reeve's name. 

 Callistochiton elenensis, however, closely resembles Callistochiton decoratus, Carp., from 

 California, if indeed it be really distinct. The most pronounced sculpture occurs in 

 Callistochiton palmulatus, Carp., also from California. 



Mr E. A. Smith has described : Callistochiton coppingeri, a form closely allied to the 

 above, but apparently sufficiently distinct from it, which also comes from Port Jackson. 



C. — LOPHYKOIDEA. 



Genus Chiton, Linne\ 

 Cliiton squamosus, Linne. 



Chiton squamosus, Linn6, Syst. Nat., 1767 (ed. 12), p. 1107 ; Deshayes, Lamarck's Hist. Nat. 

 Anim. s. vert. (ed. 2), 1836, vol. vii. p. 490 ; Sowerby, Conch. Illust., 1841, p. 

 2, No. 13, pi. clxii. fig. 76 (var.); Gray, Proc. Zool. Soc. Lond., 1847, p. 66, 

 and Guide to Moll., 1857, p. 180; Reeve, Conch. Icon., 1847, pL iii. fig. 16, 

 pL iv. fig. 23 (var.); Tristram, Proc. Zool. Soc. Lond., 1861, p. 403. 

 s, Reeve, Conch. Icon., 1847, pL xiv. fig. 77, a and b. 



Habitat— Station 36. April 22, 1873. Bermudas. Lat. 32° 7' 25" N, long. 65° 4' 

 W. 30 fathoms. Coral. Two specimens. 



West Indies. 



Although there is some doubt concerning several of Linnets species of Chitons, 

 conchologists are now quite agreed as to which form they accept as Cliiton squamosus, 

 Linn., and it is usually regarded as the type-species of the genus as commonly restricted. 

 The brothers Adams selected Cliiton aculeatus, Linn., as the type of the genus Cliiton as 

 restricted by them, and they have been followed by other naturalists in this and in the 

 use of the generic name Lophyrus for those Chitons with large, smooth, imbricated scales. 

 Dall has discussed this question in his paper On the Scientific Results of the Exjjloration 

 of Alaska, 2 and he agrees with Carpenter in taking Chiton tuberculatus, Linne, as the 

 type of the restricted genus Chiton. Concerning this latter species Dall says : " It is 

 1 Zool. Collect. H.M.S. "Alert," 1884, p. SO. 2 Proc. U.S. Nat. Mm, 1878, p. 300. 



