606 Surface Fauna of the Bay of Fundy. 
this difference are hard to define, they exist and are recognizable by 
a specialist. In the Museum of Comparative Zoology at Cambridge 
this difference is shown by faunal assemblages of life from different 
regions of the globe, each arranged in different rooms, known as 
the North American, European, African, ete. The idea is a grand 
one, and to a student of physical geography of the greatest 
importance. 
As in the study of land animals there is a different facies to the 
assemblages of life from different quarters of the globe, so in the 
ocean there is a different facies in collectious of animals from 
different regions of the sea. Place side by side a number of Arctic 
species of shells and those of the same genera from the tropics. If 
the shells be representative, the conchologist need not hesitate long as 
to their homes. The dull,cold, little variegated molluscs of the Arctic 
contrast markedly with the brilliant, gaudy shells of the warmer 
zones. Passing to the inhabitants of the ocean, the deep-sea animals 
have an altogether different facies from the surface animals. The 
characteristic facies of great regions of the ocean are as noticeably 
different as those which naturalists have long recognized «mong 
terrestrial animals. It is not in place here to point out the different 
regions into which the oceanic faunz may be divided, but it would be 
interesting in considering the causes of the boreal character of the 
pelagic life of the Bay of Fundy, as they involve a general con- 
sideration of the laws which have led to the diversity of these 
faunæ. I consider the temperature of the water as a most import- 
ant influence in causing the diversity of life in the ocean. Varia- 
tion in temperature is probably more important than pressure in 
the bathymetrical distribution of deep-sea life. The difference in 
temperature of the surface of the ocean is one of the most importan 
factors in determining the character of pelagic organisms. As we 
have a variety in surface temperatures, we have a diversity in the 
surface fauna. We have, it is held by some, a repetition of Hum- 
boldt’s law of the modification of plants in altitude, and the corre- 
spondence of latitude with altitude, in a change in character of 
animals by depth resulting from several conditions, among which 
may be mentioned pressure and temperature. Whenever the tem- 
perature of the deep-sea becomes a surface temperature, as in the 
Arctic Ocean, then, it is argued, we may look for allies of deep-5e@ 
animals. 
