; ~><) '.K'MiKAIMIK'AL D I STK I 151 T I ( L\ . 



.M. Fischer concludes. Is the doctrine of evolution over- 

 thrown by the Tacts M. |>a rrande has produced? I do not think 

 it. He has proved thai there existed among the ancient ceph- 

 alopods two Tcat types, which have continued separate during 

 tlie entire period of Iheir existence: but the evolution of each 

 of these types remains extremely probable, and conform 

 observations made upon them. In such maltcrs one cannot, in 

 clleci. ask ]nore than a probability." : ' : 



. Oeoi/rci]i/i i<-<il ])ixl rtliulioii. 



MoM. of the species of Octopods and the Nautilus are 

 littoral in habit, and have thence been conjectural to enjoy 

 luit a limited distribution; and which is held to jus;ify ; he 

 multiplication of species. This reasoning is. however, falla- 

 cious, as it is well known lha; many Ii':or:il mollusks. not 

 nearly so well provided wi.h menus of swimming, have he- 

 come world-wide in dist ribui ion. I shall show hereafter, not 

 only that particular species of Ociopus are known to inhabit the 

 shores of distant countries, but thai a lanrc proportion of these 

 species which have been distinguished by slight and mutable 

 characters, and by their geographical disi ribuiiou. will probably 

 Deed to be united when sufficiently studied. This probable ex- 

 tensive' distribution of living lilioral species- corres|)onds with 

 observations made upon fossil species of Ammonites. Nautilus 

 and other chambered genera, which are proved Jo have been 

 littoral in habit by their occurrence only in deposits representing 

 ancient sea-shores. Not to multiply examples amongst these 

 fossils, it may be mentioned that Nau/ilnx xini/)lr.r occurs in 

 Kurope. Mas; Indies and Texas; that Ammonites Botomagensix 

 is found in Kurope. Kast Indies. N. and S. Africa and S. 

 America ; and that />V/r/////rx r/mvy/s had even a i^'catcr disl ribu- 

 tion. Nevertheless, temperature has been observed to have 

 some clfcct upon the distribution of the living octopoda of 

 Mnro|>e. similar but distinguishable forms or species inhabiting 

 its northern seas, from those of the Mediterranean. As in Mol- 

 luscan life ji'ene rally, the development of specific forms has been 

 greatest in tropical waters. 



Jour, de Zool, iv, 419, 1877. 



