68 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



It is a common species on the coasts of Europe and the Arctic seas and 

 Osburn has recorded it from arctic America and down the east coast as 

 far as to Cape Cod. It does not seem to have been noted on the Pacific 

 coast, but there are specimens in the Hancock collections from Punuk 

 Island in the Bering Sea and Cleveland Passage, Frederick Sound, Alaska. 

 Common at Point Barrow, Alaska, G. E. MacGinitie, collector, Arctic 

 Research Laboratory. 



Callopora exilis (Hincks), 1882 

 Plate 6, fig. 8 

 Membranipora exilis Hincks, 1882:249. 

 Callopora exilis, O'Donoghue, 1926:33. 



Zoarium encrusting, thin. 2^oecia distinct, rather regularly elliptical ; 

 the opesia occupies nearly all of the front and averages 0.40 mm long by 

 0.26 mm wide; walls low, well calcified, the descending cryptocyst nar- 

 row and smooth on its inner border; gymnocyst often well-developed. 

 There are two pairs of small distal erect spines, and on each side are 4 

 to 6 small spines which bend slightly over the opesia. Occasionally there 

 is a small avicularium on the side of the lateral wall, just outside of the 

 row of spines ; it is so obscure that it is easily overlooked. 



The ooecia are small, rounded, prominent, without a rib, and smooth 

 or with minute striations, 0.26 mm wide by 0.20 mm long. 



Hincks described the species from Houston Stewart Channel, Queen 

 Charlotte Island and O'Donoghue recovered it from Banks Island, Vic- 

 toria, British Columbia and added to Hincks' description. 



Canoe Bay, Alaska, 125 fms, U. S. Alaska Crab Investigation, Sta. 

 24-40. 



Callopora lineata (Linneaus), 1758 

 Plate 6, figs. 4 and 5 

 Membranipora lineata^ Hincks, 1880:143. 

 Callopora lineata, Osburn, 1923 :7D. 

 Callopora lineata, O'Donoghue, 1926 :32. 



Zoarium encrusting. Zooecia moderate in size, averaging about 0.60 

 mm long by 0.35 mm wide; gymnocyst usually well-developed, occupy- 

 ing about one-third of the length ; cryptocyst moderate, granulated, with- 

 out horizontal lamina. Opesia elliptical or a little narrowed distally; 

 walls beset with about 7 spines on each side, the two distal ones erect, 

 the others bending somewhat over the opesia. Avicularia elevated on the 

 gymnocyst, usually single (sometimes a smaller pair) with triangular 

 mandible. 



