THE EUROPEAN SEAS. 



171 



place as to southern forms in their range north. 

 Haliotis tuherculata, which extends through the 

 whole Lusitanian zone, is larger at Guernsey — which 

 is its extreme northern limit — than elsewhere. 

 Ringicula auriculata and Mactra rugosa are larger 

 in Vigo Bay than in the Mediterranean, though at 

 Vigo they are both outliers ; and Tellina balaustina, 

 which has its numerical maximum in the Mediter- 

 ranean, is largest about the Hebrides. 



"With the exception of the upper extremity of 

 the Adriatic, the sea-coast dredged by Mr. Jeffreys 

 is the most northern portion of the Mediterranean, 

 and it is more purely marine, for the large rivers 

 which pour into the shallow waters of the Adriatic 

 modify its fauna in a perceptible degree. 



Mr. M 'Andrew has given the results of his dredg- 

 ings along a part of the Mediterranean coast of 

 Spain (Murcia), which lies about 500 miles south of 

 Nice, and where he obtained 353 species of Testacea. 

 These two local assemblages admit of comparison; 

 their numbers, omitting Mr. Jeffreys' new species, 

 are very close, and the portions of coast examined 

 were of about the same extent. The result is that 

 the two sets are nearly identical; the specific diffe- 

 rence for the most part hardly deserves notice. 

 Cymba olla reaches up the Spanish coast as far as 

 Malaga, so that it has a Mediterranean range cor- 

 responding to its Atlantic one. Solarium luteum 

 and S. stramineum reach so far, but have not been 

 observed farther, whereas on the Atlantic side they 

 extend to the north coast of Spain. 



