NO. 2 OSBURN: eastern pacific BRYOZOA CHEILOSTOMATA 367 



spines which soon disappear. The operculum is well chitinized, yellow, 

 with a broad, lateral sclerite which divides beyond the muscle attach- 

 ments, one band continuing distally around the margin while a much 

 narrower branch continues at some distance within from the border. 

 The avicularia are long-pointed, often paired and located usually at the 

 sides of the aperture about opposite the cardelles and directed more or 

 less laterally and backward; not infrequently they are single and more 

 proximally located, occasionally median or nearly so and directed back- 

 ward ; the mandible may be as much as 0.30 mm long but usually is 

 much shorter; attached by an incomplete pivot. 



The ovicell is hyperstomial, closed by the operculum, hemispherical 

 and prominent, with numerous small pores, somewhat marginated 

 around the base. 



Described by Canu and Bassler from the Galapagos Islands. 



Hancock Stations: 143-34, Wenman Island, Galapagos, 100-150 

 fms; 239-34, Port Utria, Colombia, shore collection; 431-35, Octavia 

 Rocks, Colombia, 45 fms; and 275, Raza Island, Gulf of California, 

 28°48'00''N, 113°00'00"W, at 40 fms. 



Genus STEPHANOSELLA Canu and Bassler, 1917 



Buffonellaria Canu and Bassler, 1927. 



"The ovicell is hyperstomial and embedded in the distal zooecia. It 

 opens above the apertura by an especial orifice. The frontal is a smooth 

 olocyst. No spines. The ovicelled zooecia have a large apertura and 

 their avicularium is frontal." (Canu and Bassler, 1917:40). Genotype, 

 Eschara biaperta Michelin. 



Later (1930:16-17) Canu and Bassler withdrew the genus and re- 

 ferred biaperta to Schizopodrella because of the "tremocystal" frontal. 

 "Our genus Stephanosella has no further reason for existence and should 

 be suppressed." Still later Bassler (1935:207) returned to the use of 

 Stephanosella. 



The confusion arose when Smitt (1873:46) and Hincks (1880: 

 255) combined with biaperta Michelin another species which has a 

 similar ovicell but a tremocystal frontal. Busk (1859:47, ? Lepralia 

 biaperta) correctly interpreted the species and Smitt in his earlier work 

 (1867:14) also figured his Escharella linearis forma biaperta correctly 

 with areolar pores only. Also Nordgaard (1906:15-16) had the true 

 biaperta. 



