BY H. FARQUHAR. 



303 



Zealand was almost as strong with that of Australia in early 

 Tertiary times as at the present day (New Zealand Geological 

 Report for 1892-1893 [1891]. p. 127). 



Of Holothurians we have twenty species, omitting Pso'us 

 macquariensis, Dendy; for it will probably be found that the 

 marine fauna of the Macquarie Islands is not New Zealandian, 

 but Antarctic. Six of these were obtained from deep water by 

 the " Challenger." The rest (fourteen species) appear to be 

 endemic. 



Thus we see that nearly all the Ophiuroids and most of the 

 Asteroids are endemic, while all the Echinoids, except perhaps 

 Goniocidaris umhraculum, occur elsewhere, a large number of 

 them being widely ranging forms. The littoral Holothurians, on 

 the other hand, are all peculiar to New Zealand. When we 

 consider the immense effect of currents in the diffusion of marine 

 animals, it appears that the eggs or plutei of most Echinoids 

 remain free for a considerable time, and are capable of being 

 transported long distances without being destroyed, so that the 

 littoral species are usually widely diffused. Some of the Asteroids 

 in their young state apparently remain free for a considerable 

 time, and are widely dispersed by marine currents; many species, 

 however, cannot be conveyed across wide stretches of ocean, and 

 are confined to very limited areas of distribution. Very few 

 Ophiuroids are capable of being transported across wide oceans, 

 being either but a short time free or incapable in their young 

 stage of enduring changes of temperature, and being tossed about 

 for some time on the surface of the sea. No doubt many of them 

 are viviparous, and are thus confined to very limited areas, as is 

 the case with Ophiopeza cylindrica. Even viviparous species, 

 however, which live on seaweed may become widely dispersed by 

 being transported on masses of floating seaweed. This is probably 

 the case with Oiihiotiiijxa australis, which is viviparous. The 

 eggs or young of the littoral Holothurians only remain a short 

 time free or are too delicate and easily destroyed to be transported 

 long distances on the surface of the sea. 



