IREDALE : LAND MOLLUSCA OF THE KERMADEC ISLANDS. 371 



To the ground were confined — 



Familum expositum (Moiisson). 



Kieconcha Kermadeci (Pfeifier). 



Ptychodon pseutes, Iredtile. 



P. amandus, Iredale. 



Charopa Macgillivrayana, Iredale. 



C. exquisita, Iredale. 



Paralaoma Paoulemis, Iredale. 



P. ambifina, Iredale. 



Tornatellina Novoseelandica (Pfeiffer). 



2\ sp., conoid form. 



3. Systematic Account. 



The account herewith given is purely concliological. I am 

 incompetent to deal with the anatomy of the snails obtained, though 

 I have ample material in spirit which will be placed at the disposal 

 of any anatomist willing to study and report upon them. It must be 

 understood that the notes given here are mainly critical and are based 

 upon shell features alone, and I would point out that I must conclude 

 that even in the study of land Mollusca a fair consideration should 

 be given to shell characters M'lien attempts at classification are made. 

 I find that Mollusca with heterogeneous shell characteristics are 

 lumped together because some small anatomical feature is found 

 constant, while shell;^, conchologically similar, are placed far apart on 

 account of anatomical differences. Tliere seems to be more reason in 

 the latter procedure than in the former, but the anatomist seems to 

 have outdone his brother conchologist in confusing material with 

 immaterial differences. It is also imperative that for the study of 

 zoogeography the exact generic location should be ascertained if 

 possible, since the more restricted the genus the more accurate will 

 be the conclusions drawn. The placing of a shell in any genus does 

 not help much, and the consequcTit differentiation in the ensuing part 

 is due to an attempt to observe the relationships of the molluscs 

 collected. I shall have further to say on this subject under the 

 generic names utilized. 



Genus Hklicarion. 

 Relicarion, Ferussac, Tabl. Syst. Moll., 1821, p. 24. Copy in Brit. 

 Mus. (Nat. Hist.). 



Type (by subsequent designation), 11. Cuvieri, Ferussac. 

 Helicarion Kermadecensis (Smith). 

 Vitrina Kermadecensis, E. A. Smith, Ann. Mag. Nat. Hist., ser. iv, 



vol. xi, p. 288, 1873. 

 Vitrina ultima, Mousson, Journ. de Conch., vol. xxi, p. 110, pi. vii, 

 fig. 1, 1873. 



I£ah. — Sunday Island, Kermadec Group. Living upon the under- 

 side of the leaves of the nikau palm on the highest point of the 

 island only. 



The generic reference would seem in this case to be easy, as Smith 

 compared it with Strangei, Pfr., an Australian species, which should 



