Iredale. — Mollusca of the Kermadecs (fir/ Norfolk Island. 503 



A minute tree-dwelling pupoid form would have been classed in Neso- 

 pupa save for the fart that the mouth was unarmed. Almost facsimiles, 

 but with fully armed aperture, have been examined from Tahiti. I drew 

 attention to the lack of arming in the aperture by creating the new genus 

 Pronesopupa, thereby suggesting the greater antiquity of my shell. I did 

 this as I noted that juvenile Tahitian shells were similarly unarmed. Neso- 

 pupa and its allies are typically Polynesian, no form whatever being known 

 from New Zealand. The Tornatellinids are unnamed, for reasons given ; but 

 I studied them a little, and I can state that of- the five species three were 

 typically Polynesian, whilst Suter has recorded one as occurring at the 

 Kermadecs and north New Zealand. In the latter case it may have only 

 recently reached New Zealand, as undoubtedly the fifth, which is referable 

 to a very distinct genus, Elasmias, is at present hfing carried about the 

 Pacific. I strongly feel that it is a comparatively recent settler on the 

 Kermadecs, and, as it is very rare at Lord Howe Island, may have also 

 recently arrived there. 



This review will indicate that the Kermadec land Mollusca tell us very 

 little, save that they apparently show their source to have been northern 

 in preference to southern. When contrasted with the Norfolk Island mol- 

 luscs much more will be seen. 



V. Digest of the Norfolk Island Land Mollusca. 



The Norfolk Island main-island living forms are of most interest in this 

 connection : and, firstly, Dendrolamellaria matthewsi is of peculiar value, as 

 this is a species perhaps referable to the family Helicarionidae, but of such 

 peculiarities in the shell alone that Dendrolamellaria would appear justifi- 

 able as a genus. It recalls the marine genus Lamellaria in form, and is 

 quite unlike the Kermadec Helicarion in every detail. Its ancestry at the 

 present moment is quite obscure. 



Aclvena campbellii is what has been known as Rotula campbellii. The 

 shell differs in character from that of Rotula, which, moreover, is a genus 

 confined to Mauritius. It is a fine handsome shell, and its character can 

 be estimated from the fact that its nearest relative was ever supposed to 

 be the Mauritius shell. Anatomical study may later give us some clue to 

 its affinity. 



The three species classed in Green tvoodoconcha are such as are often 

 referred to Microcystis, and one recalls that genus, which was first described 

 from Pitcairn Island, in its colour-markings. These shells are, however, 

 somewhat solid. The half-dozen species of AUenoconcha would probably 

 also have been placed under Microcystis, but they differ appreciably in 

 shell characters, and the shells are very fragile. One species of Microcystine 

 shell has been classed under the north Australian genus Nitor, as the shell 

 features agree quite closely with that genus. None of these Microcystine 

 genera closely resemble the Kermadec Kieconcha, the Nitor having the 

 most likeness. 



A most beautiful species was called Trochonanina platysoma by Sykes. 

 Another species has been discovered by Mr. Roy Bell, and for these the 

 genus RoybeUia has been formed. The shell, in its depressed shape, recalls 

 Fametesta mi nihil is Pilsbry. from the Bonin Group, but upon comparison 

 the Norfolk Island species is found to differ in texture entirely, being a 

 much more beautiful and delicate shell. As animals have been preserved, 

 we shall later learn of the affinities of this remarkable form. It vaguely 

 suggests itself as a relation of Fanulum. 



