il6 ON THE LItTOEAL FAtJNA OF N. E. AUSTRALIA, 



be a new species, and requires examination. Tlie first is very 

 common and equally so on tlie coral reefs. Both these species 

 keep above the tidal marks, but just within reach of the surf and 

 spray. 



Besides the Ostrea, which may be regarded as representing 

 0. mordax, there is a larger species, a Chama and a Spondylus, all 

 common, Purpura, fPolytropaJ tuberculosa is common also, but 

 not so large as the specimens found at Port Jackson. The rocks 

 are also conspicuously covered with two species of JBalanus which 

 are unknown to me as yet. One is a pyramidal form not observed 

 further south. 



Thus it will be seen that the tropical littoral fauna of the rocks 

 does not differ much from the fauna we meet with outside the 

 tropics. Some of the species are the same, but there is a change 

 in others ; thus the TrocJiocochlecB of the south have disappeared. 

 Instead of seeing on every rock and stone crowds of TrocJiococlea 

 aiistraUs, T. odontis, and T. constricta, the place is occupied by very 

 many species of Nerita, species which have a wide range through- 

 out the tropics. The PatellidcB are partly different, and so are 

 the Littorinidce, Planaxis sulcatus, being the common form. The 

 Trochidm are entirely different. Monodonta lahio, and Trochus 

 niloticus, T. asrulescens, and some others are frequently met with. 

 In many of the j^ools two or three species of cones will be found 

 such as C. hebraica, C. textilosa, C. capitaneus and some others. 

 Cyprea arabica is found almost under every stone. I might extend 

 the list, but this will suffice to give an idea of what is the general 

 character. 



On the rocks at Port Douglas there are few or no corals. Very 

 rarely one may meet a small patch of Porites or Favia Powerbanhiiy 

 but I never saw any other. These I may say are two of the 

 hardiest species of coral as well as the commonest in this locality. 

 Favia Bowerbanhii does not seem to mind mud or sediment, which 

 is fatal to most corals. Thus I have seen it encrusting a large 

 proportion of the stones at the mouth of the Mangrove Creek. 



