742 PROCEEDINGS OF THE NATIONAL MUSEUM. 



ANALYSIS OK TA15LI:. 



Species common to Puj^et Sound and (Jn^at Britain 8 



Species common to Ptij^et Sound and Scandinavia 5 



Species conmion to Pufjet Sound aiul iJenniaik and Heli<j;olaud 4 



Species common to Puget Sound and Spitzberj^en 6 



Species common to Puf;et Sound and Oroenland 4 



Species cominon to I'uj^et Sound and Alaska 8 



Species common to Puj^et Sound and New Enjiland 8 



Species common to Puj^et Sound and Labrador 4 



Species common to Paget Sound and Pacific coast soutli of Vancouver 3 



Taking Spitzbergen, Iceland, and Greenland together, as representing 

 the Arctic area thus far explored, and regarding the species found there 

 as strictly Arctic species, what may be called the meridional distribution 

 southward is significant: 



Arctic species in Puget Sound 7, or 70 per cent 



Arctic species in Great Britain '. 9, or 90 per cent 



Arctic species in Norway and Sweden 7, or 70 per cent 



Arctic species in Denmark and Heligoland 6, or 60 per cent 



Arctic species in Alaska 8, or 80 per cent 



Arctic species in New England 10, or 100 per cent 



Arctic species in Labrador '5 



Arctic species in California 2 



The fact that the hydroid fauna of New England is more thoroughly 

 Arctic than that of Great Britain is surprising at first sight, but maybe 

 accounted for by the fact that the Arctic current sweeps southward 

 along a great part of the New England coast. 



The fact that the Puget Sound fauna is equally related to that of 

 Great Britain, Alaska, and New England would seem to be a strong 

 indication that the distribution has been southward from the Arctic 

 regions along nieri«lioiial lines. 



The sharp differentiation between the fauna of Puget Sound and the 

 region between 'Vancouver Island and southern California shows, 

 apparently, that the limit of the Arctic fauna is not far south of Puget 

 Sound, a point much more northerly than on the Atlantic side. This is 

 doubtless due to the Japan current on the Pacific coast and the Arctic 

 current on the Atlantic coast. 



Among the species collected by Mr. Kincaid and the Young Natural- 

 ists' Society, were two which, although previously known, had not 

 before been reported from American coasts, namely, Ohelia plicata 

 Hincks- and Sertularia tenera Sars.' The latter species not having 

 been previously described in any English publication, so* far as I can 

 discover, the accompanying tigure (see Plate LXII) and description 

 may be of service. 



' All the species from Laltrador in the list. 



2 British Hydroid Zoophytes, 1868, p. 159. 



3 Bidrag til Kundskaben om Norges Hydroider, p. 20 



