NO. 2 OSBURN: eastern pacific BRYOZOA — CHEILOSTOMATA 479 



Clarion and Cllpperton Islands west of Mexico; Secas Island, Panama; 

 La Libertad, Ecuador, and abundant about the Galapagos Islands. Shore 

 to 73 fms. 



Grepidacantha setigera (Smitt), 1873 

 Plate 58, fig. 1 



Escharella setigera Smitt, 1873 :58. 



Crepidacantha setigera, Canu and Bassler, 1928 :135. 



? Crepidacantha longiseta Canu and Bassler, 1928:135. 



Encrusting on shells and corallines, the general aspect is that of 

 C. poissoni, except for the form of the aperture and the position of the 

 avicularia. The proximal border of the aperture is not straight as it is 

 in poissoni, but broadly arcuate and it is much narrower than in poissoni. 

 The setose avicularia are situated at the sides of the aperture instead 

 of proximal to it. The number of the marginal spinules is larger, 10 to 

 16. The ovicell is similar except that in final calcification it sometimes 

 has a low umbo on its top. 



In the opinion of the writer, C. longiseta Canu and Bassler is only 

 a variant of setigera. Canu and Bassler state that it differs "in its smaller 

 dimensions and its long setiform mandible," but I cannot find constant 

 differences in either character. 



Smitt described setigera from Florida (Tortugas Islands) and Canu 

 and Bassler list it from the Florida Straits; C. longiseta was recorded 

 from north of Cuba. 



Hancock Stations: 143-34, Wenman Island, 155-34 and 157-34, 

 Albemarle Island, Galapagos; 328, Cocos Island, off the coast of Costa 

 Rica. Seven colonies, ranging in depth from 18 to more than 100 fms. 



Genus MASTIGOPHORA Hincks. 1880 



"Zooecia with a semicircular orifice, the inferior margin straight, 

 with a central sinus; furnished with lateral vibracula" (Hincks). To 

 this may be added the presence of a recumbent ovicell and pore chambers. 

 Genotype, Lepralia hynd/nanni Johnston, 1847. 



Mastlgophora pesanseris (Smitt), 1873 

 Plate 58, fig. 3 



Hippothoa pes anseris Smitt, 1873 :43. 

 Mastigophora pes-anseris, Hastings, 1930:722. 



Zoarium encrusting. Zooecia of moderate size, averaging about 

 0.65 mm long by 0.40 wide; distinct with deep grooves, the front 



