1887.] MOLLUSKS ON THE VITI ISLANDS. 299 



the margins of mangrove-swamps. I also took many in similar 

 stations at Wallis Island and Samoa. I have received it from New 

 Caledonia, and, undoubtedly, it ranges throughout Melanesia. The 

 locality " Gambler Islands," usually assigned to this species, is 

 decidedly erroneous. There are no swampy lands and not a single 

 perennial stream in the group. Schmekz is also wrong in citing 

 Huahine, Society Islands, as habitat. 



This species varies considerably in shape, thickness, and in size 

 ranges from 12 to 30 millim. long. The surface is shining, longi- 

 tudinally striated, and the upper portions of the whorls are 

 sculptured by crowded spiral rows of minute granules, which, in 

 large adults, sometimes cover the whole surface of the body-whorl. 

 The lower part of the parietal region is armed with a prominent, 

 compressed, oblique fold, and just beneath is a smaller and more 

 vertical one on the columella. The peristome is rather strongly 

 labiated and sinuous above. The shape of the shell varies from 

 oblong-ovate to oblong-tnrreted, the spire is more or less produced, 

 and the base imperforated. Colour white, beneath a fulvous-yellow 

 or yellowish horn-coloured epidermis. 



Genus Truncatella, Risso. 

 1. Truncatella valida, Pfeiffer. 



Truncatella valida, Pfeiffer, Zeit. Malak. 1846, p. 182; Mon. 

 Auric. (Appendix) i. p. 184 ; Jav, Cat. Shells, 1854, p. 253 ; Kiister, 

 Mon. p. 11, pi. 2. figs. 7, 8, 19-21, 23; H. & A. Adams, Gen. 

 Moll. ii. p. 311 ; Martens, Ostas. Zool. ii. p. 262; Paetel, Cat. 

 Conch, p. 118 ; Pease, Proc. Zool. Soc. 1871, p. 477. 



Truncatella vitiana, Gould, Proc. Bost. Soc. Nat. Hist. 1847, 

 p. 208; Expl. Exp., Shells, p. 109, fig. 126; Otia Conch, p. 40; 

 H. & A. Adams, Gen. Moll. ii. p. 311 ; Pfeiffer, Mon. Pneum. ii. 

 p. 6; Mousson, Journ. de Conch. 1869, p. 356, 18/0, p. 195; 

 Paetel, Cat. Conch, p. 118; Schmeltz, Cat. Mus. Godeff. v. p. 104. 



Truncatella vitiacea, Mousson, Journ. de Conch. 1865, p. 185. 



Taheitia vitiana. Pease, Proc. Zool. Soc. 1871, p. 477. 



Truncatella conspicua, " Bronn," Pfeiffer, Mon. Auric. (Appendix) 

 i. p. 184 ; Paetel, Cat. Conch, p. 118; Layard, Cat. Land & Fresh- 

 water Shells N. Caled. p. 1. 



This species occurs in abundance in all parts of the group, and 

 lives just above high-water mark in sheltered places. It occurs also 

 in the Samoa, Tonga, and Ellis group, and is diffused throughout 

 Australasia and the East-India Islands. 



It may be characterized by its solid texture, slightly tapering 

 cylindrical form, white, luteous, corneous, or ruddy corneous colour, 

 and 4| slightly convex persistent whorls. The sculpture consists of 

 nearly erect, obtuse ribs (25 to 35) on the body-whorl, and the base 

 is more or less distinctly carinated. The peristome is thick, slightly 

 expanded and auriculated at the suture. The operculum is thin, 

 convex, smooth, with an elastic lamina-like margin. 



Length 6 to 8 millim. 



