694 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



flared at the tips and thus appear somewhat larger than the ordinary 

 ones. I have not been able to find any aperture on the four brood- 

 chambers in my material which I can positively identify with ooeciopores, 

 and it is therefore probable that they are similar to the ordinary aper- 

 tures. On the removal of the roof of the brood-chamber an extensive, 

 broad cavity is revealed, with the bases of the absorbed kenozoids at the 

 bottom. The peristomes of the autozoids usually traverse the cavity 

 without modification, but I have found a few which have become closed, 

 within the chamber, by a membrane with a central raised pore similar 

 to those of Diastopora. The apertures of the autozoids average about 

 0.18 mm in diameter. 



This species did not appear in the Hancock dredgings, but I have a 

 fine specimen from Friday Harbor, Puget Sound, 70 mm long by 45 

 mm wide and 40 mm high, without further data, but evidently dredged 

 locally. The encrusting base is 7 by 9 mm across, and there is a secondary 

 attachment of similar appearance by a branch, 5 mm across. Another 

 portion of a colony, loaned by Dr. R. E. Foerster, Director of the Pacific 

 Biological Station, Nanaimo, British Columbia, and bearing O'Donog- 

 hue's identification, is from Gabriola Pass, B. C. This specimen also has 

 a brood-chamber. 



Heteropora pacifica Borg, 1933 



Heteropora pacifica Borg, 1933:317. 

 1 Heteropora sp. Whiteaves, 1882:279. 

 Heteropora pelliculata, Robertson, 1910:258 (part). 

 Heteropora pelliculata, O'Donoghue, 1923:14 (part). 

 Tretocycloecia pelliculata, O'Donoghue, 1925:96; 1926:28 (part). 



(The synonymy according to Borg). 



Borg separated the more slender, more intricately branched and more 

 highly anastomosed form mentioned by Robertson and O'Donoghue as 

 a distinct species. As I have not had an opportunity to study H. pacifica, 

 I can only indicate the essential points of difference given in Borg's 

 description. 



The zoarium is erect, branching profusely and dichotomously or in 

 an irregular way. The branches frequently anastomose, giving the whole 

 colony a complexly reticulated appearance which is highly characteristic 

 of the species. The diameter of old stems is about 5 mm, of younger 

 ones 3 mm on an average. Color of dried zoaria grayish, the tips pink. 

 Autozoids with the apertures usually on a level with the surface, but 



