CEPHALODISCUS 483 
obtained. The collection of fishes has already been found 
to contain some new genera and several new species. 
There can be no doubt that many new forms will be found 
among the other groups. 
Considerable quantities of three species of Cephalodiscus 
were obtained. These animals are of interest because they 
show signs of a distant relationship to the vertebrates, 
though their mode of life is very dissimilar. The minute 
individuals live together in colonies, and build up a 
gelatinous tree-like house. 
The young forms of Cephalodiscus are very imperfectly 
known, and it is hoped that larval stages may be found 
among the material brought home, so that further light 
may be thrown upon the development of these curious 
animals. 
In the last volume of the Biological Reports it is 
proposed to review the known marine benthos of the 
continental shelves of the globe in regard to its distribution 
in time and space. One of the objects of this inquiry will 
be to ascertain, as far as our present knowledge will permit, 
if there has been any tendency on the part of the benthos 
to originate in the Northern Hemisphere and migrate 
southward. 
The work of Wallace on the distribution of land animals 
has shown that there appears to have been a tendency 
throughout the history of the earth for the land animals to 
originate in the Northern Hemisphere and gradually find 
their way south. The great belt of land which through 
long ages has almost encircled the northern half of the 
world seems to have been Nature's workshop for the 
212 
