Vaughan. — Some Corals from Kermadec Islands. 279 



Montipora caliculata (Dana) Bernard. 



1897. Montipora caliculata Bernard, Cat. Genus Montipora, p. 57, 

 pi. 9 ; pi. 32, fig. 14. 



The specimen agrees in all particulars with Bernard's description and 

 figures of M. caliculata except that the secondary septa although uniformly 

 well developed are distinctly smaller than the primaries. Dana's type of 

 M. caliculata should be in the U.S. National Museum (No. 335), but I have 

 failed to find it. 



Locality. — Meyer Island : on rock ; depth, 1 fathom. 



Acropora sp. 



Two worn fragments, not positively identifiable. 



Locality. — Kermadec Islands : Titi Knob, Sunday Island ; volcanic sub- 

 marine agglomerate. 



Alveopora sp. 



A worn fossilized specimen. 



Locality.- — Kermadec Islands : Dayrell Islet ; volcanic submarine beds. 



Art. XVIII. — On the Origin, of a Neio Species by Isolation. 



By Henry Suter. 



[Read before the Philosophical Instituti of Canterbury, 1st November, 1916; received by 

 Editors, 30th December, 1916 ; issued separately, 16th August, 1917.] 



In April, 1907, Captain J. Bollons, of the Government s.s. " Hinemoa," 

 brought back from the Great King Island a number of large snails, some 

 containing the live animal, which I described under the name of Placostylus 

 bollonsi (12, vol. 40, 1908, p. 340, pi. xxv ; 11, p. 763, pi. 30, figs. 11, a, b). 

 I pointed out that this species offered a splendid example of the origin of 

 a new species by isolation, and I now propose to go more fully into this 

 interesting subject. 



The genus Placostylus occurs with us in the northern part of the North 

 Island only, which points to its immigration from the north, and, geologically 

 speaking, most likely in comparatively recent times. Placostylus is found 

 in New Zealand, Lord Howe Island, New Caledonia, Solomon Islands, Fiji, 

 and a stray species in New Guinea. Hedley (4, p. 335) considers this Placo- 

 stylus area, New Guinea excluded, as a zoological province, a unity explicable 

 only on the theory that these islands form portions of a scattered continent 

 and are connected by shallow banks formerly dry land . This continental area 

 he calls the " Melanesian Plateau " (later named " Antarctica " by Forbes). 

 New Caledonia is, with about thirty-five species of Placostylus, the metro- 

 polis of the genus, and. some of its species are closely allied with those of 

 Lord Howe Island and New Zealand. Subfossil, one species is known 

 from Koutoumo Island, New Caledonia (P. sessilis Gassies), and two from 

 the Loyalty Group ; post-Tertiary, one from Lord Howe Island ; and 

 P. hongii ambagiosus Sut. is found in large numbers subfossil on Cape 

 Maria van Diemen. 



