AND THE FISH THEREOF. 



preferring well-overgrown declivities or zostera meadows, whilst others seek 

 the rocky shores, or the creviced precipices, according to the nature of their 

 food, tarrying, nevertheless, in the vicinity of their favourite resorts, and 

 hovering about within given limits, both horizontal and vertical. 



The sea water proper of the Adriatic, in respect of the degree of saltness, 

 is about the same as the Atlantic under the tropics, so that southern forms 

 prosper. 1 



But it has been shown that, similar to the lochs of Scotland and the 

 fjords of Norway, the salt water is often intermingled with fresh water, 

 arising from the limestone springs, which abound especially in the Quarnero, 

 so that the surface waters may be fresh, or nearly so, whilst the depths are 

 as salt as in mid-ocean. 



This circumstance alone accounts for the prosperity of single colonies of 

 otherwise foreign, and even northern forms, though not affording an 

 explanation of the question how they came there. 



The depth of the Adriatic is for the most part moderate ; the depth of 

 the Quarnero varies from 20 to 40 fathoms, and only at points it reaches 60 ; 

 proceeding south, it increases to So to 100 fathoms near the islands of Zuri, 

 Incoronata, and Scoglio Porno ; from Porno, the course of the greatest depths 

 is south-east, and near the island of Meleda the bed has not been reached at 

 500 fathoms. 



In the great variety of physical characteristics here enumerated we find so 

 many factors in favour of a high development, and furnishing the require- 

 ments for the most opposite attributes of submarine animal life. Thus it is 

 that the Adriatic offers an extensive field for the investigations of the student 

 of natural history, and is justly appreciated on this account by naturalists from 

 all parts of the world. 



Nevertheless, the fauna of the Adriatic has not been subject to a thorough 

 and systematic investigation like many other seas, such as the yEgean, the 



1 The affinity between the Mediterranean and Japanese faunas has been pointed out by 

 Dr. Gunther, the number of genera common to these two faunas being larger than that of the 

 genera common to the Mediterranean and the opposite American coasts. 



C 



