66 THE PKOCEEDINGS OF THE LINNEAN SOCIETY 



believe that they are one and the same. Indeed, it is very easy 

 to bridge over any interval when we find such a deep and open 

 sea as that which intervenes between Australia and the Mauritius 

 bridged over by the same species. I believe it to be also identical 

 with Littorina cUemanensis, Quoy (Voy. de VAst. t. 2, p. 479, pi. 

 33,/. 8, llj. Of this species M. Deshayes says, after quoting the 

 habitat of Quoy, which is simply Yan Dieman, " The Littorina 

 of Dieman is absolutely the bluish Turbo of Lamarck," which is 

 a Littorina, or as now known L. ccsrulescens. It is found, he 

 adds, in the Mediterranean, and on the English Channel. The 

 only slight difference that M. Deshayes could observe was the 

 presence of certain strias which the European specimens have not, 

 but I can answer that the Australian species are as often without 

 them. " The individuals are in general larger (he is referring 

 to the Australian shells.) Shell short, slightly swollen at the 

 base, the spire is pointed. The color is sky blue, with an 

 irregular band, rather darker in the last whorl. The aperture is 

 rounded, a little angular, and of a sombre violet within. Its 

 colors are much more brilliant under water than when exposed to 

 the air. It is 11 millim. long, by 6 wide. So far with regard 

 to the Tasmanian species. It is also said to occur in N. Zealand. 

 Captain Hutton has sent me the shells which receive this name 

 (L. diemanensis) . They came from Dunedin (nearly 46° S. lat.), 

 a very cold station for a shell whose finest and largest examples 

 are found at Port Jackson, or even as far north as lat. 30 S. 

 Consequently, as we might expect, the Dunedin specimens are 

 sordid and dwarfed. The bands of color are far more definite, 

 and the blue, or rather neutral tint predominates over the white, 

 while at Port Jackson the white predominates. The mouth is 

 much darker in the Dunedin shells, and the angle less marked at 

 the base of the last whorl. This is the rule, but intermediate 

 examples can be found at both places. The Port Jackson shells 

 have the last whorl larger than the spire, which is short and 

 tumid. The spire is longer and not tumid at Dunedin, but with 

 rounded whorls. It seems to me that the Dunedin shells may be 

 taken as an intermediate stage to Littorina cincta, Quoy, which is 

 the common form on the Dunedin coast, and at the Bluff, N.Z., 



