NO. 2 OSBURN: eastern pacific BRYOZOA CHEILOSTOMATA 307 



Zoarium encrusting, usually white or yellowish, but old colonies may 

 be deep red. The zooecia are moderately large and vary greatly in size, 

 0.55 to 0.80 mm long by 0.35 to 0.45 mm wide, arranged in quincunx, 

 distinct in younger stages with the frontal slightly inflated ; with sec- 

 ondary calcification, which proceeds very rapidly, the tremopores 

 become much enlarged at the surface which is also modified by irregular 

 nodules and granules. The primary aperture, which usually can be 

 observed only on the marginal row, is subcircular with a u-shaped proxi- 

 mal sinus ; a low, smooth peristome is present until it is overgrown by 

 the encroaching thick frontal wall ; secondary aperture short-pyriform, 

 the proximal notch more or less irregular in form. The aperture is some- 

 what removed from the distal zooecial end and, in older stages, is sur- 

 rounded by a thick, granular, raised wall except at the proximal sinus. 



Ovicells have not been observed in this species and there are no avicu- 

 laria nor spines. 



This is a high northern species, known from Nova Zembla to Green- 

 land. Hincks records it from the Queen Charlotte Islands and O'Don- 

 oghue from several localities from the San Juan Islands, Puget Sound, 

 and British Columbia. 



Off Cape Lisburne, Alaska (Arctic Ocean), 30 fathoms, and Punuk 

 Island, Bering Sea, 15 fathoms, from material in the Los Angeles 

 Museum. Also from Point Barrow, Alaska, Arctic Research Laboratory, 

 G. E. MacGinitie, collector. 



Stomachetosella limbata (Lorenz), 1886 

 Plate 34, fig. 2 



Schizoporella limbata Lorenz, 1886:6. 



Escharella linearis forma secundaria Smitt, 1867:14 (in part). 



Zoarium encrusting on shells, the color pale yellow to bright brown- 

 ish. The zooecia measure 0.50 to 0.65 mm in length by 0.30 to 0.40 mm 

 in breadth ; arranged in quincunx, distinct with large pores and slightly 

 inflated. The primary aperture is semicircular, nearly straight on the 

 proximal border which bears a narrow, rounded sinus; these characters 

 observable only on the youngest zooecia. As in other species of this 

 genus, the secondary aperture is formed by the thick frontal wall; it 

 differs somewhat in shape from the primary aperture, the proximal border 

 usually being more arcuate and the sinus is often irregular in form ; the 

 raised rim about the aperture is less developed than in the other species. 



