252 COLE 
In the table the localities are arranged in order from the north 
and west toward the east and south, from Bering Sea to southern 
California. The species are similarly arranged in the order of 
their first occurrence in the list of localities. It will be noticed 
that there is a great gap in the series of localities extending the 
whole distance from Prince William Sound, Alaska, to northern 
California, except for the single record of Stimpson at Puget 
Sound, This gap is indicated in the table by double lines. 
It seems at first surprising that more of the species are not 
identical with North Atlantic forms; but when it is taken into 
account that only four species have been found to the northward 
on the Pacific side, and that one of these, Phoxichilidium femora- 
tum Rathke, is circumpolar, being found also on the coasts of 
northern Europe, the proportion does not appear so small. Fur- 
thermore, twavother of the four species, Ammothea latifrons and 
Ammothea alaskensts, correspond fairly closely to the European 
forms Ammothea echinata (Hodge) and Ammothea levis (Hodge) 
respectively, and it is not unlikely that they have been differen- 
tiated from common circumpolar types. 
In discussing the distribution of the Hydroids collected by the 
Harriman Alaska Expedition, Nutting (: 01) takes exception to 
the definition of the Pacific faunal areas made by Dall (76) in 
‘An Introductory Note to the Report on Alaskan Hydroids, by 
Mr. Clark.’ Dall extended what he called the Oregonian Fauna 
from Monterey to the Shumagin Islands; Nutting would not 
extend this southern fauna farther northward than about the 
region of Puget Sound. Then, instead of a break at the Shu- 
magin Islands with a distinct fauna beyond (called the Aleutian 
by Dall), the results of further research would seem to show that 
from Puget Sound to the Aleutian Islands the fauna is fairly con- 
tinuous and homogeneous, and to this Nutting has applfed the 
name Alaskan Fauna. Reasoning from the close relation existing 
between Pycnogonida and Hydroid colonies, the former being so 
often found with and perhaps obtaining their food from the latter, 
and the larvz, in some cases at least, being known to be parasitic 
upon the Hydroids, either living within the gastral cavity (Dohrn, 
’81, p. 76) or attached to the outside with the proboscis buried in 
the body of the host (von Lendenfeld, ’83), it would not be at all 
