176 NUTTING [ I 58] 



In 1878 C. Mereschkowsky l added a single species to the 

 Alaskan fauna, bringing the total up to 41. 



No other additions were made until 1899, when I added eight, 

 of which three were well known British species and five were 

 new. 2 That made a total of 49 species reported prior to the 

 Harriman Expedition. 



The collection here treated of comprises 53 species, 24 of 

 which had been previously reported. Of the remainder, 9 were 

 previously recorded from other localities, and 20 are new. 

 Thus the Harriman Expedition has added about 60 percent to 

 the number of species hitherto known from Alaskan waters. 

 More than half of the species secured are new to Alaska and 

 nearly 40 percent are new to science. 



The whole number of species of hydroids now known from 

 Alaska is 78. Considering the small amount of collecting that 

 has been done in that region, compared with the extensive ex- 

 plorations of the coasts of Europe and the Atlantic coast of the 

 United States, one may confidently expect that the waters of 

 the far Northwest will prove to be very rich in hydroid life. 



GEOGRAPHIC DISTRIBUTION. 



A table is here given to indicate, first, the localities at which 

 each species was collected by the Harriman Expedition, and 

 second, the extent to which Hydroids have been distributed south- 

 ward along meridional lines from what appears to have been 

 a polar center of distribution. No attempt has been made to 

 represent the complete distribution of the species. 



A glance at the part of the table showing the distribution as 

 represented in the collection secured by the expedition, shows 

 an apparent poverty of the Hydroid fauna of the western, as 

 compared with the eastern, portion of the territory explored. 

 For convenience in such comparison the stations are arranged 

 consecutively from east to west. The largest series were ob- 

 tained at Berg Inlet in Glacier Bay ; Yakutat Bay ; and at Orca 

 in Prince William Sound. These localities are all in deep bays, 

 sheltered from storms and surrounded by rocky shores. On 



1 New Hydroida from Ochotsk, Kamtschatka, and other parts of the North 

 Pacific Ocean. Annals and Mag. Nat. Hist., Dec., 1878. 



2 Hydroida from Alaska and Puget Sound. Proc. U. S. Nat. Museum, Vol. 

 xxi. (No. 1171.) 



