398 Scientific Intelligence. Zoology. 



distribution of Crustacea^ which we shall now present to the 

 consideration of our readers. According to the views which 

 are laid down in the most highly esteemed works on this sub- 

 ject, such as those of Fabricius, Latreille, Lamark, Desmarest, 

 Sec., it would appear that a great number of these animals are 

 scattered over immense distances on the surface of the globe, 

 and inhabit equally our own coasts, and the seas of America, 

 as well as the Indian ocean ; but an attentive examination of 

 the Crustacea which are brought from these distant localities, 

 and which hitherto have been regarded as identical species, has 

 convinced M. M. Edwards that the habitat of these animals is 

 much more circumscribed than has been generally imagined. He 

 has determined, that with the exception of some of the Crustacea 

 of the wide sea, which for the most part repose on floating fuci, 

 or live as parasites upon fish, all the American species are dis- 

 tinct from those of the European seas, and that these again are 

 all different from those of the Indian ocean. " So far as the 

 Crustacea are concerned, remarks M. Edward, many zoological 

 regions exist, having each a particular population which is partly 

 composed of organic types, whose analogues are not found else- 

 where, and another part consists of the representatives of species 

 which also exist in other regions. Thus our river crawfish does not 

 exist in America, but is there replaced by a neighbouring species 

 of the same genus ; Southern Africa possesses a third species of 

 the same animal, and this organic type is also found in New Hol- 

 land, but with distinct specific characters. Results altogether 

 analogous are presented by the Palemon, Langoustes, Pa- 

 gures, Lupees, &c. M. Edwards also remarked that each of 

 these great regions is the head-quarters, so to speak, of certain 

 organic types, some representatives of which, however, are 

 found in other seas. Thus the poriuni properly so called be- 

 longing almost exclusively to the seas of Europe ; though 

 some have been found even on the coasts of New Holland ; and 

 in the seas of Asia and America these Crustacea are to a certain 

 extent replaced by the Thalamites and the Lupees. These great 

 regions, which are completely distinct from each other, are 

 nevertheless in close proximity : thus the northern coasts of Af- 

 rica belong to the European region, whilst the Red Sea consti- 

 tutes a portion of the region of the Indian ocean. Finally, each 



