432 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



The ovicell, according to O'Donoghue's description and figure is 

 characteristic of the genus, "globose, hemispherical and projecting, and 

 its surface perforated by a series of large irregular pores." 



There can be no question as to the position of this species in the 

 genus Rhamphostomella. Similarly I have no doubt that Srnittia tor- 

 quata O'Donoghue is merely the young stage of his 5. cellata as the basic 

 characters are the same and the only differences are due to advanced 

 calcification and the presence of the ovicell. 



Described from British Columbia and recorded from numerous lo- 

 calities there and about the San Juan Islands in Puget Sound. 



Dr. J. L. Mohr collected the species for the Hancock collections at 

 Middle Bank, Puget Sound. 



Rhamphostomella ovata (Smitt), 1867 

 Plate 50, fig. 6 



Cellepora ovata Smitt, 1867:31. 

 Rhafnphosto?nella ovata, Nordgaard, 1906:32. 

 Rhamphostomella ovata, Osburn, 1912:248; 1919:610. 

 Discopora ovata, Nordgaard, 1918:78. 



Zoarium encrusting on stones and shells, occasionally on stems. The 

 zooecia are smaller than those of our other species, averaging about 0.70 

 mm long by 0.45 mm wide, elongate oval, regularly arranged in quin- 

 cunx; the front is evenly arched, with a number of large pores in 

 addition to the areolar pores, the costae if present short and not prom- 

 inent. The avicularian chamber is comparatively small, usually reaching 

 only to the midline; the umbonate process small and low, consisting 

 chiefly of the avicularian rostrum which bears on its lateral face a small 

 elliptical avicularium with a round-tipped mandible. The primary 

 aperture is rounded, 0.28 to 0.30 mm long and wide, the proximal 

 border often a little asymmetrical. There are no cardelles and in our 

 specimens no lyrulae ; rarely vestigial oral spines on very young zooecia. 

 (Nordgaard, 1906:34, lists this species among those which have a 

 "median denticle," but I have never found it in all the Atlantic and 

 arctic specimens I have seen.) The secondary aperture is more or less 

 asymmetrically ovate, the slightly overhanging base of the avicularium 

 producing a straighter edge at that side. 



The ovicell hemispherical, prominent, smooth and imperforate when 

 young, but becomes rough when covered by secondary calcification. 



