THE EUK0PEAN SEAS. 



117 



guicula, Mitra, Cymba, Marginella (as distinguished 

 from Erato), and Conus, none of which are present 

 in the Celtic fauna. 



We find also the lost traces of some northern 

 forms, as Venus striatula, Pecten maximus, Ostrea 

 edulis, Acmcea virginea, and Littorina neritoides. 

 With the exception of the last-named species the 

 peculiar littoral assemblage of Testacea which holds 

 its place from Nordland to Finisterre, and reap- 

 pears, as we have seen, for a space in Gallicia, has 

 entirely disappeared. 



The Echinoderms of the Lusitanian seas are 

 kinds common to the Mediterranean, and not Celtic 

 species. The Echinus esculentus verus is the charac- 

 teristic sea-urchin. 



Probably in the present state of our knowledge 

 the most marked distinctions between the Lusi- 

 tanian and the Celtic regions are to be founded on 

 the Testacea. The presence of members of the 

 series of genera I have mentioned above, is espe- 

 cially a most unmistakable distinction, besides 

 the numbers of species which do not range north- 

 wards of the Peninsula. The general assemblage 

 of species, especially those which inhabit the lit- 

 toral and laminarian zones, presents a much more 

 gay and gaudy painting than in more northern 

 seas. From the Mediterranean region, on the other 

 hand, a number of peculiar Testacea, absent there, 

 afford a distinction. Such are the Chiton fulvus, a 

 large and singular species, which, contrary to the 



