230 LITTORAL DISTRICTS. 



Australian District (PI. B). 



By far the most typical of all the districts is the Australian, so peculiar 

 that wo might be tempted to ((insider the fauna of Echini a.s belonging to 

 a different period, were they not contemporaries of some of the species of 

 the Indo-Pacific, East Indian, Japanese, and of the Indo-African Districts, 

 from all of which there are species extending far into the Australian Dis- 

 trict. This region includes also the New Zealand Islands; they have one or 

 two species thus far limited to the northern islands, which have not yet 

 been found on the Australian coast, — Laganum rostratum and Evechinus 

 chloroticus. 



The characteristic feature of the Australian District is the existence of so 

 many species of Amblypneustes and Holopneustcs, genera remarkably lim- 

 ited in their geographical distribution. The typical species are: — 



Goniocidaris geranioides, Amblypneustes pallidus, 



Goniocidaris tubaria, Amblypneustes griseus, 



Stephanocidaris bispinosa, Amblypneustes ovum, 



Centrostephanus Rodgcrsii, Amblypneustes formosus, 



Salmaeis globator, Eupatagus Valenciennesii, 



Ilolopneustes porosissimus, Breynia Australnsiae, 



Holopneustcs inHatus, Linthia australis. 

 Ilolopneustes puipurescens, 



Ilolopneustes and the succeeding genera were formerly represented in the 

 Nummulitic Period of India, and the Tertiaries of Europe ; they have, how- 

 ever, totally disappeared from the European seas. 



NuRTII ClECUMPOLAR DISTRICT (PL A). 



This district is characterized by a single species only, — S. Drobachiensis. 

 It extends far into the North Atlantic District, and is associated on the 

 American shores with the Boreal American and the North Pacific species, 

 lapping part of the Japanese and Calil'ornian Districts, and extending to the 

 Lusitanian District on the European shores. 



