NO. 2 OSBURN: eastern pacific BRYOZOA CHEILOSTOMATA 303 



Described from the Gulf of Mexico at 29 fms by Smitt, and recorded 

 from the Gulf at 30 fms by Canu and Bassler; also from Aruba Island, 

 Gulf of Venezuela, 23 fms by Osburn. 



Hancock Stations: recovered at 16 stations from Espiritu Santo 

 Island, Gulf of California, to a little south of the equator, and from 

 shore to 133 fms, but not abundant anywhere; 2186, Cabeza Ballena and 

 299, San Jose del Cabo, at the tip of Lower California; 223 and 136-34 

 and 137-34, Clarion Island; 132-34, Socorro Island; 431-35 Octavia 

 Rocks, Colombia; the following from the Galapagos Islands, 85-33, 

 North Seymour Island; 147-34, 155-34 and 461, Albemarle Island; 

 and 454 and 473, Hood Island. 



Family GigantOpOridae Bassler, 1935 



Galeopsidae Jullien, 1903. 



Characterized by the presence of a large pore (spiramen) extended 

 into a tubule proximal to the aperture, wanting in some cases, or a pair 

 of avicularia directed across the aperture. The ovicell is hyperstomial, 

 opening into the peristomice above the aperture. 



The two genera of the present work may be distinguished as follows : 



1. Zoarium encrusting; boreal and arctic .... Cylindroporella 



2. Zoarium erect, zooecia all facing the same side, avicularia on the 



dorsal side, tropical Semihaswellia 



Genus CYLINDROPORELLA Hincks 1877 



Zoarium encrusting. Zooecia more or less terete, the proximal end 

 usually much narrowed, the distal end elevated into a high tubular 

 peristome which bears a small tubular ascopore near its base. Frontal 

 with numerous small pores. Ooecium hyperstomial. No avicularia, no 

 spines. Genotype, Lepralia tubulosa Norman, 1868. 



Cylindroporella tubulosa (Norman) 1868 

 Plate 35, fig. 2 



Lepralia tubulosa Norman, 1868:308. 

 Porina tubulosa, Hincks, 1880:230. 

 Porina tubulosa, Osburn, 1912 :233. 

 Cylindroporella tubulosa, Osburn, 1933 :34. 



Zoaria encrusting, usually small, on shells. The zooecia are some- 

 what terete, the proximal end often narrowed to a point, very dis- 

 tinct, the front ventricose and perforated with numerous small pores. 



