408 REVIEWS AND BOOK NOTICES. 
We are not so sure but that Forbes’ notion was in the main the 
more correct one. Certainly from the facts presented in this book, 
we should gather the impression that the circumpolar fauna tended 
Fig. 107. 
Bathybius Hæckelii. 
to fade out, even at great depths off the mouth of the Mediterra- 
nean Sea; and the few arctic forms dredged off Florida by Pour- 
talès are mingled at great depths with a much greater abundance 
of tropical invertebrate life. But the facts brought out by Pour- 
