176 COLLECTIONS FROM MELANESIA. 



sufficient to say " Mers australes," New Holland, or Australia in 

 dealing with a continent which extends over 30 degrees of latitude 

 and 40 of longitude, howsoever wide the distribution of the dwellers 

 on its shores may he ; nor could it be permitted by one who would 

 study a collection of Port-Jackson specimens, and then take up the 

 corresponding forms from Port Molle or Torres Straits (cf. Tables 

 I.— V. of Distribution). 



Ophiuroidea. — Ophiopinax stellatus, described from Singapore, and 

 found by the ' Challenger ' at lat. 11° 37' N., long. 123° 32' E., has 

 now been found at Port Molle, Port Denison, and Torres Straits. If 

 Oplriothrix fumaria has been correctly identified, this is apparently 

 the first time that a definite locality has been ascribed to it ; 0. 

 martensi has been shown to be very common in the Australian 

 seas ; 0. galatece (from the Nicobars) and 0. punctolimbata (Java) 

 have their distribution extended eastwards ; 0. rotata has been ex- 

 tended from Mindanao to Thursday Island ; and 0. ciliaris, known 

 from the "Indian Ocean," has been seen to appear at Port Jackson. 



If we might with justice attempt any generalization from such 

 facts as tbese, we should be led to a belief in the significance of the 

 free-swimming larva as affecting the extent of the distribution of 

 not-stalked Echinoderms. 



AYith regard generally to the Echinoidea, it may be said that in 

 seven cases we have the area of distribution increased : Diadema 

 setosum, Scdmacis bicolor, Tcmnopleurus toreumaticus*, T. gramdosus 

 have never yet been found on the eastern coast of Australia ; 

 Cli/peaster hvmilis and Maretia plamdata have been reported from 

 New Caledonia, but not from such a locality as Port Molle or Clair- 

 montf. Temnoph wrus bothryoides, found by the 'Challenger' in the 

 Arafura Sea and Kobi, Japan, is now known from an interme- 

 diate locality. The members of this class bear ample witness to the 

 now well-known fact that Indian-Ocean and Pacific specimens in- 

 vade largely the Australian seas. 



A question which presented itself to me, but on which I can throw 

 but little light by way of answer, might perhaps be formulated thus: 

 "What differences are there between the forms of the eastern and 

 northern and the western coasts of Australia ? 1 



To the south of the East-Indian islands there lies an area of deep 

 sea almost free from islands, and having sweeping across it, in obedi- 

 ence to the laws of motion, a current with a south-westerly direction 

 from the equator ; this current sweeps, as we know, round the Cape 

 of Good Hope, and there comes into contact with the southern con- 



* Mr. Tenison-Woocls reports it from " all the coasts of Australia, but rare 

 outside the tropics." 



t But M. plamdata was taken at Port Jackson by tbe ' Challenger ; ' the 

 presence of this species in the Australian seas is additionally interesting from 

 the fact that a form allied thereto. M. anomala, has been described by Prof. 

 Martin Duncan (Q. J. Geol. Soc. xxxiii. p. 52). 



J For Echinoderms, as for Fishes (see Giinther, ' Introd. Study of Fishes,' 

 p. 284), the western half of the south coast of Australia is still almost a terra 

 incognita. It is earnestly to be hoped that the investigation of this area may 

 be soon undertaken. 



