

498 Transaction*. 



Art. XLVITI. — A Comparison of the Land Molluscan Faunas of the 

 Kermadec Group and Norfolk Island. 



By Tom Iredale. 



Communicated by W. R. B. Oliver. 



[Bead before the Auckland Institute, 16th December, 1914.] 



I. Introduction. 



In the Proceedings of the Malacological Society of London, vol. x, pp. 364-88, 

 1913, will be found a detailed account of the land molluscs of the Kermadec 

 Group. I had hoped to review this fauna as a zoogeographical item, and 

 contrast it with that of the other island groups which have been generally 

 named in connection with this group — viz., Lord Howe Island and Norfolk 

 Island. But my own collection consisted mostly of minutiae, and I was some- 

 what surprised to find that the minute molluscan fauna of these groups was 

 unknown. Since then, however, a very large and varied collection of the 

 land molluscs of Norfolk Island has been made by Mr. Roy Bell, my friend 

 and companion collector at the Kermadecs, who has obtained large quan- 

 tities of minute forms. Still, no general review can be made, as no col- 

 lections of minute forms are yet known from Lord Howe Island, the Fiji 

 Group, or New Caledonia. As, however, Norfolk Island, has always been 

 a favourite study of the Neozelanic zoologist, especially on account of the 

 former existence on that island of species of birds of the Neozelanic, other- 

 wise endemic, genera Nestor and Hemiphaga, I propose herewith to make 

 a comparison between the land molluscs known from the Kermadecs and 

 from Norfolk Island. 



II. List of the Kermadec Group Land Mollusca. 



In my collection made at the Kermadecs only twenty species were 

 represented ; previous to my arrival at the island six species were on record, 

 and, as two were not recovered by me, sixteen species were added. All 

 these were minute forms. 



One of the most interesting results was the discovery that the molluscs 

 were divisible into two groups — one composed of species which lived upon 

 trees, and which were not found on the ground save through adverse cir- 

 cumstances, such as falling leaves ; whilst the other group consisted of 

 species which lived under stones, leaves, logs, &c, on the ground, and were 

 never found upon trees. The tree-dwelling molluscs were,— 



Helicarion kermadecensis (Smith). Pronesopupa senex Iredale. 



Ptychodon royanus Iredale. 

 Calymna arboricola Iredale. 

 Flammulina miserabilis Iredale. 

 Oharopa pseudanguicida Iredale. 



To the. ground were confined,- 



Fanulum expositum (Mousson). 

 Kieconcha kermadeci (Pfeiffer). 

 Ptychodon pseutes Iredale. 



amandus Iredale. 



Oharopa macgillivrayana Iredale. 

 exquisita Iredale. 



Tornatellina sp., a slender form. 



sp., near bilarnellata Anton. 



Elasmias inconspicua (Brazier). 



Paralaoma raoulensis Iredale. 



- ambigua Iredale. 

 Tornatellina novoseelandica Pfeiffer 



(? = si ib perforata Suter). 



- sp., a conoid form. 



