THE MOLLUSCA HEDLEY. 417 



TRUNCATELLA YALIDA, Pfeiffer. 

 PfeifFer, Zeits. Malak.,1846, p. 182; Conch. Cab., i., "Truncatella," 



1855, p. 11, pi. ii., figs. 7, 8, 19, 20, 21, 23. 

 Truncatella vitiana, Gould, Moll., U.S. Explor. Exped., 1852, p. 



109, pi. viii., figs. 126, 126a, 1266. 



Abundant at Funafuti where it has already been found by 

 Graeffe.* This belongs to a semi-marine, semi-terrestrial assem- 

 blage of which I have already written that "The smallest islands 

 which possess any life at all are usually stocked by these forms, 

 which appear to range from Ceylon in the west, to the Sandwich 

 Islands in the east, and to be limited north and south by the 

 tropics."! 



Gould remarked that T. vitiana, admitted to be variable in 

 size, " is not very different from T. valida" The differences in 

 sculpture, small perforation, basal keel and posterior fusion of the 

 ribs, on which he relied to separate the two, are shown by a series 

 before me to be quite inconstant features. Smith says,! " When 

 the genus is re-monographed, it is probable that some older name 

 will be discovered to replace that of valida." A sentence which 

 admirably expresses the assistance tendered by London writers 

 to students of the Pacific Mollusca. 



OMPHALOTROPIS ZEBRIOLATA, Mousson. 

 Mousson, Journ. cle Conch., xiii., 1865, p. 181, pi. xiv., fig. 11 ; xxi , 



1873, p. 108 ; Garrett, Proc. Zool. Soc., 1887, p. 308. 

 mplialotropis rotumana, Smith, Ann. Mag. .Nat. Hist., (6). xx., 

 1897, p. 552. 



Abundant under sticks and stones on the main islet of Funafuti. 

 It had already been found here by Graeffe, who also observed it 

 at Nukufetau, Vaitupu, and Niutao in the Ellice, Nukuiona, 

 Uvea, Kanathia, Fiji, and Wallis Island. Authentic specimens 

 of the unfigured 0. rotomana enable me to confidently unite 

 this with Mousson's species. Some such conclusion seems indeed 

 to have been anticipated by Smith, who alludes to this and others 

 as likely to "eventually prove to be slight variations of already 

 known species." 



ASSIMINEA NITIDA, Pease. 

 Garrett, Proc. Zool. Soc., 1887, p. 314. 



Abundant on Funafuti, where it had already been collected by 

 Graetfe. 



Garrett, who gives a complete bibliography says : "This small 

 species is generally distributed throughout all the groups from the 

 Paumotus to the Viti Islands and New Caledonia." 



* Mousson Journ. de Concb. xxi.. 1873, p. 109. 



t Hedley Proc. Linn. Soc. N.S.W. (2) vi., 1891, p. 101. 



I Smith Journ. Malak. v., 1896, p. 21. 



Cc 



