110 ON THE LITTORAL T ATTN A. OF N. E. ATJSTRALLA., 



Tasmania it is unknown, on tlie east coast it is very rare, and 

 then they are only poor, small, and distorted specimens. About 

 the region of Port Jackson it attains its maximum of development 

 and is sometimes an inch and more in length. But it is not 

 common inside the harbour. It is only seen at intervals along 

 the east coast and I did not notice it about Cape Moreton or in 

 Moreton Bay. I did not see it at any place on the coast, except 

 Port Douglas, and there the size never exceeded a quarter of an 

 inch. The climate appears to stunt its growth completely, though 

 preserving its colour and shape. The result is interesting as a 

 climatial influence if we compare its efiorts with what we should 

 witness if particular regions were to affect horses or cattle in a 

 similar way. In contrast with this we have a remarkable 

 illustration of the effects of climate in an exactly different manner. 

 The rocks are frequently covered with a large species of Acmcea, 

 which may have been described many times by different observers 

 as it varies so much. It is common on all parts of the east coast 

 which I have visited and equally common on Tasmania. It 

 passes into Bass' Straits, but is not common on the south coast. 

 In Tasmania it may be seen at its lowest state. It is small, 

 irregular in growth, very much stunted, and sordid in appearance. 

 Though not at all uncommon it is not easy to recognize on the 

 rocks. The best point of resemblance throughout is the peculiar 

 mottled spathula which is very characteristic and never can be 

 mistaken. It is a true Acmcea, with the giU plume at the back of 

 the neck, and by this feature also and the peculiar ribbed structure 

 it can always be known. As it is traced northward from the 

 extreme south of Tasmania, where I first saw it and described it 

 as a new species under the name of Acmcea marmorata. (See Proc. 

 Boy. Soc. Tas. 1875, p. 153.)itgradually increases in size and the 

 colors of the shell become brighter and more clear. It can be 

 thus followed over the Straits and on to the Australian coast. It 

 receives its maximum of development in North-east Australia ; 

 thus inhabiting a line of coast from South Tasmania to Cape 



