Farquhak. — On New Zealand Echinoderms. 195 



reef formed of soft sandstone fringes the shore, forming a com- 

 paratively level floor, a miniature " plain of marine denu- 

 dation," intersected by numerous narrow clefts, which are 

 never free from water at the lowest tides. When I was a boy 

 I have often observed great numbers of this species along the 

 sides of these clefts, just below low-water mark, in rounded 

 cavities which they had themselves hollowed out of the soft 

 rock. Mr. E. Lukins, of the Port, Nelson, has kindly verified 

 this observation for me recently. The Maoris collect large 

 numbers, which they cook and use for food. Numerous 

 broken and denuded tests may be found on the shores after 

 storms. This species varies considerably in form, some speci- 

 mens being much more depressed than others. Many are 

 circular when viewed from above, while others are more or 

 less pentagonal. 



The range of this species is interesting and somewhat re- 

 markable. It does not occur in Australia, where many of our 

 Echinoderms have been found, but specimens were collected 

 bv the naturalists of the " Challenger " Expedition at the Fiji 

 Islands. If this stood alone it would be simply one of those 

 interesting facts which our present knowledge is inadequate 

 to explain. When, however, we consider it in connection 

 with the fact that a large number of our plants and animals, 

 some of which are eminently characteristic of the New Zea- 

 land region, have representative forms in Norfolk Island, Lord 

 Howe Island, and New Caledonia, the distribution of our sea- 

 urchin assumes an important significance, reminding us of 

 times long ago — probably early Pliocene — when the continent 

 of which New Zealand of to-day is but a remnant extended 

 far to the north and west. The southern branch of the south 

 tropical current, which passes the Fiji Islands and sweeps 

 down the eastern coast of Australia, was then deflected south- 

 wards by this northern extension of New Zealand, and facili- 

 tated the diffusion of Polynesian plants and animals to New 

 Zealand.* 



E. chloroticus has been found fossil in Pliocene formations 

 at Wanganui. 



Although our species does not occur in Australia there is 

 a very closely allied form found there, E. australe, described 

 by the Ptev. J. E. Tenison- Woods from specimens obtained near 

 Port Jackson (Proc. Linn. Soc. N.S.W., vol. ii., p. 167, and 

 Dr. Eamsay's Catalogue Ech. in the Aust. Mus., pp. 24, 53). 

 It appears to be rare, and, unlike the New Zealand form, does 



* For proofs of the former extension of New Zealand, and affinities 

 of our fauna and flora, see " Proofs of the Subsidence of a Southern Con- 

 tinent during Recent Geological Epochs," by M. Blanchard, N.Z. Journ. 

 of Science, vol. i., 1883; and "On the Origin of the Fauna and Flora of 

 New Zealand," by Professor Hutton, ibid., vol. ii., 1884. 



