NO. 2 OSBURN: eastern pacific BRYOZOA CHEILOSTOMATA 297 



Gycloperiella rosacea Osburn, 1947 

 Plate 32, figs. 5-8 



Cycloperiella rosacea Osburn, 1947:31. 



Zoarium encrusting, rose red to reddish purple. Zooecia moderately 

 large, 0.55 to 0.75 mm long by 0.40 to 0.50 mm wide, a little inflated 

 and distinct; frontal a thick tremocyst with large infundibulate pores. 

 The thin peristome is surrounded and obscured by an oral shield 

 developed from the frontal. The apertura is suborbicular, straighter 

 on the proximal border, 0.16 to 0.18 mm long by 0.15 mm wide. The 

 operculum is well chitinized, with a strong sclerite on each side, run- 

 ning from the attachment forward inside of the border. Rarely a small 

 avicularium with a triangular mandible situated at the side of the 

 aperture and directed forward or toward the peristome. A low umbonate 

 process sometimes is present proximal to the aperture. 



The ooecium is large, 0.30 to 0.35 mm wide, globular and promi- 

 nent, the surface a rough tremocyst like the frontal, partially covering 

 the aperture. The peristome of the fertile zooecia is much more elevated 

 than in the infertile zooecia and extends around the sides of the aperture 

 to fuse with the ovicell; often rising into lappets which sometimes 

 bend toward each other across the aperture. 



There is much variation in the size of the zooecia and especially 

 in the number and distribution of the avicularia; often whole colonies 

 show no avicularia, but rarely nearly every zooecium will have one 

 or more near the aperture or more proximally on the front. 



The species was described from the Caribbean Sea, several localities 

 along the north coast of South America. I can find no differences between 

 Atlantic and Pacific specimens. The only other species known is the 

 genotype, C. rubra Canu and Bassler 1923:127, from the Miocene 

 and Pliocene, Virginia to South Carolina and Jamaica. 



Hancock Stations: 129-34, Socorro Island, 137-34, Clarion Island, 

 west of Mexico; 155-34, Albemarle Island and 458, Indefatigable 

 Island, Galapagos; 322, Bahia Honda, Panama; 457-35, Secas Islands, 

 Panama. Also at Albatross Sta., 2824 and 2825, off Espiritu Santo 

 Island, Gulf of California. Depth range 14 to 60 fms. 



