NO. 2 OSBURN: eastern pacific BRYOZOA CHEILOSTOMATA 515 



Robertson recorded the species from Puget Sound and O'Donoghue 

 listed it for several places in British Columbia. 



U. S. Alaska Crab Investigations, Sta. 60-40, Leonard Harbor, 

 Alaska, and Sta. 61-40, Cold Bay, Alaska, 15 to 25 fms. Also taken by 

 Prof. G. E. MacGinitie at Point Barrow, Alaska, Arctic Research 

 Laboratory, 13 to 22 fms. 



Myriozoum tenue O'Donoghue, 1923 

 Plate 64, figs. 7-9 



Myriozoum tenue O'Donoghue, 1923 :39. 



Zoarium similar to the other species of the genus but more slender. 

 Zooecia also similar, indistinct, the frontal with large pores, but narrower 

 than in the other species. The primary aperture is distinctly shorter, 

 but with the same straight proximal border and deep sinus. The avicularia 

 are minute, round, typically paired but well separated and located near 

 the aperture just above its distal border; not infrequently there is only 

 one present but in the same position. 



The ovicell, as in other species, is hyperstomial, deeply embedded, 

 first appearing as a low rounded swelling and later becoming completely 

 covered by the front of the distal zooecia. Their presence may be noted, 

 as O'Donoghue states, by their occurrence "in bands about two zooecia 

 deep around the stem and so form an annular enlargement." 



The slender form, the shorter aperture and the presence of the 

 minute paired avicularia are the distinguishing characters. 



Described by O'Donoghue from Departure Bay, Buccaneer Bay and 

 Swiftsure Shoal, British Columbia, 15 to 25 fms. 



Albatross Station 2886, off the coast of Oregon, several fragments. 



Genus MYRIOZOELLA Levinsen, 1909 



Levinsen, in his synopsis of the genera of Myriozoidae, 1909:297, 

 states merely "Avicularia without transverse bar; pore chambers," and 

 indicates the genotype, Myriozoum crustaceum Smitt {Lepralia plana 

 Dawson, 1859). 



The zoarium is encrusting, the zooecia indistinct without separating 

 grooves, the frontal a tremocyst with large pores, the aperture with a 

 transverse proximal border and a deep narrow sinus; avicularia paired 

 beside the aperture; ovicell hyperstomial, subimmersed, perforated like 

 the frontal. 



