1 SO Simmons, Remarks about the Relations of the Floras etc. 
For convenience I have usecl different signs to mark the 
distribution of families ( — ) and genera (X). 
Before going into detail with the conclusions that can be 
drawn from the above table, it will be useful to summarize 
the distribution of the families as follows: 
Table IX. 
Arctic 
Not arctic 
Atlantic 
Atlantic- 
pacific 
In most Seas 
Northern and 
Southern tem- 
perate and 
cold Seas 
Atlantic 
Atlantic 
pacific and 
Southern 
In most Seas 
Only 
Indian Ocean 
Total 
Phaeophyceae 
1 
1 
10 1 
4 
— 
2 
19 
Bhodophyceae 
— 
— 
14 ! - 
1 
i 
4 
1 
21 
Together 
i 
1 
24 1 
5 
i 
6 
1 
40 
Out of 40 (marine) families 27 are represented in the Arctic 
Sea and of these again 24 have a wide distribution in most 
parts of the oceans. As the families, mostly at least, represent 
very old types it is natural that they should have spread so 
far. About the age of the few families, that have a more 
narrow area, it is hardly possible to have any opinion, but for 
the three arctic ones it seems most probable that the following 
preglacial homesteads must be supposed: for Lithodermataceae 
the Polar Sea, for Tilopteridaceae the sea south of the tertiary 
landbridge. That the Didyosiphonaceae have been represented 
in the tertiary Polar Sea can hardly be doubted, but on the 
other hand they have another area of distribution in the south, 
probably also old, as they are represented there not only by 
a Didyosiphon (?) but also by an endemic genus Scytothamnus. 
Of the 13 families not present in the arctic regions 6 have 
a wide distribution , and 5 others only are represented in the 
atlantic area. The latter are all such as only have a very 
limited number of species. Probably these lead their origin 
from the tertiary-atlantio flora. One family, Gloiosiphoniaceae , 
laas a distribution somewhat similar to that of the Didyo- 
siphonaceae and may perhaps have been present in the tertiary 
Polar Sea, although it is now entirely wanting in those waters. 
As can be seen of the table IX, there is only a single family, 
Acrotylaceae , that is entirely absent from the Atlantic. Perhaps 
this ocean really is richer in different algae than other seas, 
most probably however this apparent greater abundance of 
forms is due in a great measure to the better exploration of 
those waters. Future research.es perhaps will make it necessary 
to take another view upon the history of some of the above- 
