506 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Gostazia costazi (Audouin), 1826 

 Plate 62, figs. 3-4 



Cellepora costazii And.o\xin, 1826:7. 



Cellepora costazii, O'Donoghue, 1923 :48 ( ? part). 



Costazzia costazii, O'Donoghue, 1926:75 ( ? part). 



Not Cellepora costazi, Robertson, 1908:313 (see C. robertsoniae) 



Zoarium pisiform or terete on small stems, less frequently incrusting 

 flat surfaces. Zooecia moderate in size, young marginal ones 0.55 to 

 0.65 mm long by 0.35 to 0.40 mm wide, without orientation except at 

 the margin (and only partially so there) ; distinct with the terminal 

 tubular portions well separated. The frontal is irregularly roughened, 

 usually with several pores in addition to the areolar pores and these are 

 usually carried up on the front in later calcification. The primary aper- 

 ture at the bottom of the peristome is noticeably longer than broad 

 (about 0.17 mm long by 0.13 wide), rounded with a rather deep 

 V-shaped sinus. The peristome is moderately high, with a pedicellate 

 avicularium on each side rising above the peristome and with the 

 small ovate avicularia turned more or less toward each other across the 

 aperture. Spatulate avicularia, varying in size are sometimes present 

 among the zooecia, but are often wanting from whole colonies. 



The ovicell is wider than long (0.28 by 0.20 mm average), attached 

 moderately high on the peristome, smooth and glossy; the characteristic 

 semicircular frontal area with a row of radiately arranged pores extends 

 in full width across the front above the orifice. 



The records of Robertson and O'Donoghue are in doubt as both of 

 them have confused costazi with robertsoniae Canu and Bassler. Robert- 

 son indicates the presence of a third avicularian process on some of her 

 specimens, and the "var. erectd' of O'Donoghue is certainly robertsoniae 

 with erect stems and the ooecia "sunk to the level of the general surface." 



Robertson's records are from "south shores mainly," California, and 

 those of O'Donoghue from numerous localities in British Columbia. 



Hancock Stations: dredged only twice, at Station 1205-40, San 

 Nicolas Island, and ofif San Pedro Breakwater, California, numerous 

 colonies, down to 20 fms. There are also specimens from San Francisco 

 Bay. It is apparently much less abundant than the related robertsoniae. 



