1886, } Zoblogy. 655 
position above the cesophagus. In those fishes which continued 
to use air, as the Dipnoi, the sac became cellular and more com- 
plex. Its weight would then cause it to sink below the cesopha- 
gus, as we find.it in Polypterus. From this stage the lung of air- 
breathers was derived. In those fishes which became most 
esophagus, while the lungs are on the ventral side. He there- 
fore regards the swim-bladder of Polypterus as a true lung, while 
t of Lepidosteus is a swim-bladder. In support of his view 
that these organs are respectively not homologous, he states that 
Diodon and Tetrodon possess both swim-bladder and lungs. The 
latter he recognizes in the diverticula from the lower side of the 
‘esophagus, with which those fishes inflate themselves. He also 
Sees a rudimental swim-bladder in diverticula ffom the superior 
side of the cesophagus which occur in some animals, for instance, 
in the pig. ; 
THE FORMER SOUTHERN LIMITS OF THE WHITE OR POLAR 
Bear.—In my remarks on the occurrence of the white bear in 
ing over the accounts of the early discoverers and navigators, as 
Well as Cartwright's “Journal,” I am led to materially alter my 
Opinion and to supposes that the former limits of this creature 
extended even possibly as far south as Casco bay, on the coast of 
ine, 
Whether there are any notices of or references to the white 
ar in the records and sagas of the Norsemen who visited the 
tian Cabot in Hakluyt’s Voyages (111, 27): 
I 
” 
