36 



THE FISHERIES OF THE ADRIATIC, 



In the second instance, — horizontal distribution, 



limited extended 



extended vertical distribution in the Quarnero 27 9 



limited to one zone 103 27 



both of which results (we quote Dr. Lorenz) would speak against the theory 

 of Professor Forbes (a theory which in the case of Algst is fully borne out), 

 viz., — that an "extended" vertical distribution speaks, at the same time, for an 

 "extended" horizontal distribution, and vice versa. 



At any rate, the greater number of species, which, according to this 

 theory, should have an "extended" distribution, belong, on the contrary, to 

 the "limited" distribution in whichever sense we chose to comprehend the 

 term "limited"; on the other hand, however, it is fully borne out in the 

 instance of some species, such as, — Ophiotrix fragilis, Asteracanthiou 

 glacialis, Echinus microtuberculatus^ Xantho rivulosus, and Portunus Roncleletii, 

 which are distributed throughout most of the zones, and have, likewise, a 

 wide horizontal distribution, even as far as the Indian Ocean and the Arctic 

 regions. 



The lower we proceed the higher becomes the percentage of Northern forms. 



The following table shows the horizontal distribution of those species 

 whose general distribution is known : — 



1 Of which 4 are almost exclusively Boreal. 



2 Of which 3 ditto ditto. 



3 Of which 3 extend to the Arctic regions. 



