NO. 2 OSBURN: eastern pacific BRYOZOA CHEILOSTOMATA 401 



Zoarium encrusting (Alder describes it as rising in convoluted frills 

 from an encrusting base) thin and flat. Zooecia large (0.65 to 0.95 mm 

 long, 0.45 to 0.70 mm wide), regularly disposed in series or quincunx, 

 little inflated, the frontal with numerous pores, the marginal ones not 

 enlarged. The primary aperture is rounded, about 0.20 mm wide, with 

 small cardelles and a broad lyrula (in young colonies the lyrula is often 

 narrow, which may explain the pointed lyrulae of Johnston's figure). 

 The peristome is high and thin, enclosing or at least fusing with the 

 rostrum of the suboral avicularium and the secondary aperture is more 

 or less pyriform (subtriangular on ovicelled zooecia). The suboral avicu- 

 larium is small, little elevated but projecting forward over the lyrula, 

 the chamber small, the mandible semicircular or slightly longer than 

 broad. The large spatulate frontal avicularia described on British speci- 

 mens have not been found on Pacific colonies. 



The ovicell is comparatively small, 0.26 to 0.30 mm broad, prominent 

 at first but later considerably immersed, porous like the frontal. 



Cosmopolitan (if the records are all correct). San Pedro, California, 

 Robertson ; numerous localities in British Columbia, O'Donoghue. 



Hancock Stations: too numerous to list, ranging from the coast of 

 Oregon to the Galapagos Islands. Also from Canoe Bay and Leonard 

 Harbor, Alaska, Alaska Crab Investigation. 



Smittina spathulifera (Hincks), 1884 

 Plate 47, fig. 3 



Smittia Spathulifera Hincks, 1884:52. 



The zoarium is encrusting and flat. The zooecia are similar to those 

 of S. landsborovii, as large or even larger, sometimes more than 1.00 mm 

 long, little inflated, regularly arranged in quincunx, with a delicate, 

 slightly raised bordering line. The frontal is a tremocyst with numerous, 

 moderately large pores. The primary aperture is also similar, except 

 that the lyrula is even broader, but the secondary aperture is quite dif- 

 ferent as the peristome does not enclose the avicularium and the lyrula 

 is fully exposed within the short "sinus." The avicularium is at a little 

 distance from the proximal border of the aperture and is not enclosed in 

 the peristome folds, much larger than in landsborovii; the mandible is 

 horizontal and short spatulate or long oval ; the chamber varies much in 

 size but is always low and flat and appears to be embedded in the frontal 

 wall, sometimes occupying as much as the median third for nearly half 

 of the frontal length. The frontal pores are naturally occluded in the 

 area occupied by the chamber, but in rare cases when the avicularium 



