NO. 2 osburn: eastern pacific bryozoa — cheilostomata 309 



Stomachetosella abyssicola new species 

 Plate 34, figs. 4-6 



Zoarium encrusting on rock, unilaminar. Zooecia large, 0.85 to 1.05 

 mm long by 0.65 to 0.80 mm wide ; very distinct, with raised separating 

 lines, considerably ventricose. The frontal is a coarse, granulated tre- 

 mocyst with large, scattered pores, the marginal ones larger and separated 

 by short costae. The primary aperture is transversely elliptical, broadly 

 arcuate on the proximal border, about 0.20 mm wide by 0.14 mm long, 

 without cardelles or lyrula, sloping downward distally. The operculum 

 is well chitinized, with a narrow bordering sclerite. The peristome is 

 raised high on each side into a thick lappet and in the infertile zooecia 

 is continued as a thinner raised rim around the distal border, the sec- 

 ondary aperture being somewhat ovoid and narrowed proximally. There 

 are no spines and no avicularia. Multiporous septulae are present. 



The ovicell is large, prominent, semilunate, partially surrounding 

 the aperture, 0.40 mm wide, cucullate with a large orifice which is not 

 closed by the operculum ; its texture like that of the frontal, granulated, 

 with a few small pores; resting on the base of the distal zooecium but 

 scarcely embedded. 



The character of the frontal, the form and nature of the primary 

 aperture, the operculum, and the peristome which unites with the cor- 

 ners of the ovicell to form a high wall around the aperture with a nar- 

 rowed proximal "rimule spiramen," appear to ally this species with 

 Stomachetosella. The ovicell is less deeply embedded than in other 

 species of that genus, but perhaps this may be the result of the thinner 

 wall of this abyssal species. 



Type, U.S. Nat. Mus., 11028. 



Type locality. Albatross Station D.5685, at 645 fms, off Abreojos 

 Point, west coast of Lower California, 25°42'45"N, 113°38'30''W. 



Genus POSTERULA JulHen, 1903 



Front bordered by a line of areolar pores; primary aperture oval, 

 without sinus or cardelles; secondary orifice elongate-pyriform, with a 

 deep, irregular sinus within which are one to several small avicularia. 

 Ooecium small, hemispherical, becoming completely embedded. Geno- 

 type, Escharoides sarsii Smitt, 1867:158. 



