THE EUROPEAN SEAS. 



153 



They all live in shallow water, and attain a great 

 size. Cucumaria pentactes, which reaches far north, 

 was taken there, as was also the Syrinx nudus. 



Some of the Echinoderms of the Mediterranean 

 illustrate the changes of range in latitude which 

 the same species exhibit when we compare present 

 faunas with those of past times : a large and beau- 

 tiful urchin found in the Crag formation of our 

 eastern counties is identical with the Brissus Scittm 

 of the Lusitanian regions. 



Crabs, Lobsters, and Shrimps, belonging to the 

 order Crustacea, are rich, both numerically and in 

 species, throughout the European seas, and they 

 admit of a like geographical distribution to that 

 which has been noticed with respect to other 

 marine forms of life. M. Milne Edwards, who has 

 devoted much time and study to these animals, 

 was the first to present a sketch of this sort, and 

 indicate those zoological provinces into which the 

 European seas may be divided. Some species are 

 peculiar to the Scandinavian region, others to the 

 Celtic. The Mediterranean, again, contains species 

 which are not to be met with in either ; so that, 

 with respect to Crustacea, he considered that the 

 European seas presented three distinct regions. 

 The west coast of Africa has its peculiar Crusta- 

 ceans, constituting a fourth region, and the Atlantic 

 islands might, perhaps, form a fifth. This " Celtic 

 region" of M. Milne Edwards is of much greater 

 extent than that which Ed. Forbes designates by 



