296 THE PROCEEDINGS OF THE LINNEAN SOCIETY 



that singular Polyzoary named by Prof. Busk, Lunulites cancellata. 

 The other is a form which approximates to Geratotrochus but 

 differs in the absence of any special ornamentation on the ribs and 

 the wide deep calice, with a very large hispid and spongy 

 columella, and a broad attachment. 



In referring to these corals as extratropical, I must define what 

 I mean by the term. The reef-builders are not exactly confined 

 to the tropics in N.E. Australia ; they extend a little beyond it 

 and may be found as low as lat. 28° S., or even lower. It seems 

 to me that there was formerly a prolongation of the Barrier Reef 

 to the south. If the map of N.E. Australia be consulted it 

 will be seen that to the north of Moreton Bay there is a large 

 island jutting out somewhat east of north. This is marked on 

 the maps as Great Sandy Island, but is locally known as Frazer's 

 Island. It is separated from the coast line on the south, by Wide 

 Bay. The land on both sides seems to consist of immense drifts 

 of red and yellow sand irregularly stratified. To the north the 

 island ends in a coral reef called Break-Sea Spit, and then the 

 reefs are continued with long interruptions in islands and coral 

 shoals, including Lady Eliot's Island, Bunker's group, Capricorn 

 group, &c. until the Barrier Beef is reached. Strictly speaking, 

 Wide Bay may be said to be the commencement of that inner 

 channel which continues inside the Barrier Beef right up to Cape 

 York, a distance of about 1200 miles. It would be more con- 

 venient therefore, in the study of Australian corals, to designate 

 as belonging to the extratropical fauna, all south of Breaksea 

 Spit. Of the west side I can say little or nothing. The shell 

 fauna of Perth has certainly more of the Indian Ocean in its 

 fades, than Australia ; and the raised beaches of Freemantle are 

 unquestionably tropical in their fauna. I should incline to the 

 opinion that the extratropical fauna should not be made to extend 

 beyond the south west cape, Cape Leuwin. The coral reefs of 

 Houtmans Abrholhos are iii lat. 28*59. 



I must add a few words as to the classification of corals which 

 I am sure will become daily a greater matter of difficulty, as the 

 variation of different species comes to be better understood. In 



