132 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I28 



measured 22 mm. wide and 18 mm. high. This is the first record 

 from the Pacific side of the Arctic. 



Without doubt Pachyegis princeps (Norman) is the most abundant 

 and conspicuous encrusting species at Point Barrow. It forms coarse, 

 reddish-brown colonies on stones and shells, sometimes completely 

 enveloping a stone. There was scarcely a stone taken from 175 and 

 453 feet without at least one colony of this species. It occurred from 

 no to 741 feet. The yellowish-brown P. hrunnca (Hincks) is also 

 common. Both species are new to the western Arctic. 



Although not abundant, Porella compressa (Sowerby) is a common 

 and conspicuous species that forms large foliate colonies up to 100 mm. 

 high and wide. It was taken from no to 522 feet. One large colony 

 from 522 feet had three species of bryozoans, young barnacles, an 

 annelid (Spirorbis), many Foraminifera, and a compound tunicate 

 Didemnmn albidum growing on it. It is new to the Pacific side of 

 the Arctic. 



Seven species of RhamphostomeUa were taken, including the new 

 R. gigantea Osburn, which forms large colonies of erect, foliate ex- 

 pansions and frills that rise to a height of 80 mm. and vary in color 

 from greenish yellow to bright yellowish orange to deep orange. Colo- 

 nies were taken from 80 to 420 feet. 



Costasia nordenskjoldi (Kluge) occurs abundantly, forming white, 

 almost globular masses about 5 to 8 mm. in diameter that surround 

 stems of hydroids, bryozoans, holdfasts of tunicates, etc. It is new 

 to the Pacific area of the Arctic. 



The branching forms Costasia surcularis (Packard) and C. ventri- 

 cosa (Lorenz) were in hauls from no to 741 feet. The latter species 

 bore ovicells on October 11, 1949, and eggs were present on August 17, 

 1949. Both species are new to the western Arctic. 



The beautiful branching Myriosoum subgracile d'Orbigny forms 

 large white colonies sometimes 8 inches high. A very large colony 

 matted with sponge and with hydroids growing from the sponge was 

 taken at 125 feet. It is new to the Arctic. 



Suborder Ctenostomata 



The soft encrusting Alcyonidium polyotim (Hassell) was usually 

 found on shells {Buccinum and Neptunea), on barnacles, and hold- 

 fasts of tunicates. Colonies taken from 453 and 149 feet were bearing 

 ovicells. Colonies from 152 feet contained eggs that averaged 112 

 microns in diameter. It is new to the western Arctic. 



Species of Alcyonidium seem to be given to unusual shapes but 



