294 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



It is a large coarse species in comparison with P. collaris Norman 

 (a specimen from Norman's collection sent me for comparison by Dr. 

 Anna B. Hastings of the British Museum) and resembles it only in 

 its general appearance. It evidently belongs in the genus Hippopodina 

 and it shows a close resemblance to H. feegeensis (Busk) and H. 

 vestita (Hincks), except in the absence of avicularia which are also 

 often wanting in H. feegeensis. 



Robertson recorded it as P. collaris from one locality, "45 fathoms 

 on the west coast of the island of Santa Catalina, oflf the coast of southern 

 California." 



Type, AHF no. 56. 



Type locality, Hancock Station 1232-41, five miles off San Pedro 

 breakwater, 33°38'30"N, rx8°12'20"W, at 18 fms. Other stations, 

 1017, 1201 and 1371-41, Santa Catalina Island; 1023, 1283-41, 1284-41 

 and 1295-41, Santa Rosa Island; 1241, San Miguel Island; 1242, Ana- 

 capa Island; 1303-41, Santa Cruz Island, all off southern California; 

 1190, Cortez Bank, off San Diego Bay, California; 270 and 271, 

 Angel de la Guardia Island, and 283, San Pedro Nolasco Island, off 

 Guaymas, Sonora, Gulf of California. The known distribution is from 

 the northern Channel Islands, off southern California, to San Pedro 

 Nolasco Island in the Gulf of California, N. Lat. 28° ; bathymetric 

 range 15 to 131 fms. 



Genus ROBERTSONIDRA new genus 



The frontal is a pleurocyst (little more than an olocyst but with a 

 thin secondary layer), with a row of areolar pores, the surface with 

 numerous small papillary tubercles, covered by a thick ectocyst; a small 

 pointed umbo centrally placed proximal to the aperture. The primary 

 aperture is semicircular, the proximal border broadly arcuate or nearly 

 straight, no cardelles, no lyrula; operculum well chitinized, a narrow 

 sclerite separated from the border, muscle attachments on the sclerite. 

 Peristome thin, wanting on the proximal border, elevated on the lateral 

 and distal sides, no spines. Dorsal side with several tubular attachment 

 processes. Vertical walls with numerous irregularly distributed septulae. 

 Ovicell hyperstomial, large and prominent, with minute pores and a 

 small central umbo ; closed by the operculum. 



Named for Dr. Alice Robertson in recognition of her important work 

 on the Bryozoa of California. Genotype, Schizoporella oligopus Robert- 

 son, 1908. 



