134 PROF. W. J. DAKIN : EXPEDITION TO THE 



again to the birds. Another paper on the bird-life was written by Chas. G. 

 Gibson and published in the ' Emu,' 1908-1909. 



It will be seen that whilst the mammals, birds, reptiles, and amphibia have 

 been referred to by three or four 'visitors to the Abrolhos, nothing in any 

 detail has been published on the marine fauna beyond the work of Saville Kent. 



Kent considered that the marine fauna of the Abrolhos was essentially a 

 blend of tropical and temperate species. The tropical species were not to be 

 found on the adjacent coast. Rich coral growths were to be seen everywhere 

 (the islands were stated to be almost entirely composed of coral), but the 

 living species were not the extra-tropical forms to be seen on the coast in 

 this latitude, but were tropical types. 



The Percy Sladen Trust Expeditions to the Abrolhos Islands in the years 

 1913 and 1915 have been conducted, in the first place, for an investigation 

 into the structure and formation of these coral islets, and in the second 

 place for the purpose of collecting information regarding the fauna and 

 marine flora of this region of the Indian Ocean and West Australian coast. 

 In connection with the latter aim we were particularly interested in the 

 statements made by certain authors (Saville Kent, and Micbaelsen of the 

 German Expedition to South- West Australia) that the marine fauna of 

 the Abrolhos was entirely different from that of the coast in -the same 

 latitude and only 40 to 50 miles away. We have collected some data with 

 regard to the Hydrography of these regions, but it is extraordinary how 

 little is known even of sea temperatures on the Australian coast, while 

 numerous problems await investigation in connection with the tidal 

 phenomena. It is a pity that the means of communication along the AVest 

 Australian coast should be difficult and costly, but probably in the future, 

 when this large State has its present vast spaces occupied by energetic 

 emigrants; these difficulties will disappear. The time may even come when 

 the scientific investigation of these coastal waters, with their valuable 

 products of pearl-shell and fish, will be recognised as of just a little 

 importance. 



The present paper is concerned with a general description of the Abrolhos 

 Islands and includes an account of their structure and formation. Other 

 papers will follow dealing with the collections obtained on the two expeditions. 

 One paper on a new species of Enteropneusta has already been completed. 

 A short account of the Vertebrates, by Mr. W. B. Alexander, M.A., is also 

 ready. The Sponges are now in the hands of Professor Dendy, and Professor 

 W. A. Herdman has the Ascidians. The Holothurians are being worked up 

 by Dr. J. Pearson of the Colombo Museum, the other Echinoderms by 

 H. L. Clarke. The remaining groups have not yet been distributed owing 

 to the dislocation of work consequent on the war. 



The study of the marine fauna of the Abrolhos Region and the North- 

 west coast of Australia forms an interesting sequence to biological work 



