NO. 2 OSBURN: eastern pacific BRYOZOA CHEILOSTOMATA 385 



always long enough to touch the pivot of the avicularia of the adjacent 

 superior zooecia so that all of the avicularia of the same colony are in 

 direct tactile communication." I have found colonies in which the setae 

 are so long, but this is not always the case even on the same colony. 



The ovicell is globular, very prominent, granulated and perforated 

 like the frontal and there is only slight evidence of ribs around the base. 



The paired, parallel avicularia situated far forward easily distinguish 

 this species. 



Described from the Galapagos Islands, Albatross D.2813 and D.2815. 



Hancock Stations: 431-35, off Octavia Rocks, Colombia, and 307, 

 Secas Islands, Panama. 40 to 80 fms. 



Microporella setiformis O'Donoghue, 1923 

 Plate 44, fig. 8 



Microporella setiformis O'Donoghue, 1923:32; 1926:65. 



Encrusting on stones, shells, worm tubes, etc., white and shining. 

 The zooecia are moderate in size, 0.50 to 0.65 mm long by 0.40 to 0.45 

 mm wide, considerably inflated, elongate hexagonal; the frontal with 

 numerous pores and covered by shining ectocyst. The aperture is more 

 than semicircular, 0.09 by 0.12 mm, the proximal border quite straight 

 and with no indication of cardelles. The peristome is thin, smooth, 

 slightly elevated and there are 5 evanescent oral spines. The ascopore is 

 unusually small, round, slightly elevated and lacks the projecting shelf 

 which is common to most members of the genus. The avicularia are 

 paired, opposite the ascopore near the zooecial margin, the chamber 

 small and rounded, the rostrum short, the mandible setose and usually 

 less than half as long as a zoocium, directed diagonally. 



The ovicell, which O'Donoghue did not observe, is very prominent, 

 globular, 0.25 to 0.30 mm in width; appearing smooth under the 

 epitheca but when this is removed it is porous like the front and with 

 delicate radiating ribs which are enlarged at the base; on the sides the 

 ovicell extends backward around the aperture to the proximal border. 

 Rarely there is an umbonate process on the frontal. 



Described by O'Donoghue and recorded by him from 11 localities 

 in British Columbia, from the San Juan Islands northward. 



Hancock Stations: 1284-41, 1388-41 and 1152, Santa Rosa Island; 

 1064, Santa Barbara Island; 1234, off San Pedro, California. Also at 

 Hein Bank, Puget Sound, Washington, Dr. J. L. Mohr, collector. 

 Low water to 54 fms. 



