696 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



surface of the colony up to the margin of the cancellated tops of the 

 branches. In these characters our specimens agree with Borg's descrip- 

 tion of H. pacifica var. alaskensis, and the differences are so striking and 

 constant as to warrant the elevation of the "variety" to specific standing. 



On protected areas the peristomes may be as much as 0.25 to 0.30 

 mm long, though usually they are much shorter. The tips of the branches 

 are sometimes evenly rounded, but more frequently they are somewhat 

 clavate or spatulate, slightly excavated on one side where a brood- 

 chamber is located, and the rim may extend beyond and give off two 

 or three branches, thus leaving the brood-chamber in the broad fork of 

 a branch. Other brood-chambers are found on the sides of branches, 

 as shown in Borg's figure 5 (plate 10). 



The brood-chamber is typically that of Heteropora, a low, more or 

 less flat swelling, through the roof of which the peristomes of the 

 autozoids penetrate and are slightly elevated above it. On the removal 

 of the calcified membrane, or roof of the chamber, a considerable cavity 

 is exposed, traversed by the autozoid tubules and showing the remains 

 of the partially absorbed kenozoids. I have not been able to find on any 

 of our specimens the large ooeciostome figured by Borg and cannot de- 

 termine the location and form of the ooeciopore. 



This species differs from H. pelliculata Waters, 1879, which it some- 

 what resembles, by the elevation of the peristomes over the whole surface 

 and by the complete closure of the kenozoids over the whole colony up 

 to the level of the margins of the cancellated tops of the branches. The 

 same characters, as well as the smaller size, distinguish it from H. 

 pacifica Borg. As the color of our preserved specimens is white, this may 

 be the lemon-colored form recorded by Robertson (1910:259) from 

 "Channel Rock, Puget Sound." 



Our specimens are from Bentinck Islands, British Columbia, without 

 further data, loaned by Dr. W. A. Clemens of the University of British 

 Columbia, ten colonies of various forms and sizes. Also 2 fragments, 

 with ovicells, from Clayoquot Wharf, British Columbia, E. F. Ricketts, 

 collector. 



Hancock Station 1490-42, off Cape Arago lighthouse, Oregon, 43° 

 20'26''N, 124°22'24"W, at very low tide, 5 fragments. 



Genus BORGIOLA Strand, 1933 



Canuella Borg, 1933:331, (preoccupied by Scott, 1893). 



"Zoarium erect, arborescent, branching sparsely; its surface strongly 

 rugose, showing numerous irregularly shaped elevated areas and between 



