692 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Division 4. GeriopoHna Hagenow, 1851 



(Heteroporina Borg, 1933) 



The Heteropores 



"Primary zoid adnate or partially erect; zoarium varying in shape, 

 adnate, suberect or erect, composed of zoids of two kinds, autozoids and 

 kenozoids, the latter at least as numerous as the former, both autozoids 

 and kenozoids opening at about right angles to the surface of the 

 zoarium ; wall of the zoarium double, consisting of gymnocyst and 

 cryptocyst; brood chamber a coelomic space, formed by the absorption 

 of the subdistal portions of some autozoids and numerous kenozoids 

 outside the fertile, ovigerous zoid (zoarial brood-chamber)." (Borg, 

 1944:208). 



Family Heteroporidae Waters, 1880 



"Zoarium erect, pedunculate and capitate, or arborescent ; autozoids 

 and kenozoids about equally numerous or the former less in number; 

 apertures of both kinds of zoids scattered over the surface of the zoarium, 

 not forming clusters, circular or polygonal in shape; brood chamber 

 zoarial, not visible from surface except in form of a slight swelling of 

 that part of the zoarium." (Borg, 1944:209). 



Two genera are represented in our material, Heteropora Blainville, 

 1830, and Borgiola Strand, 1933 (Canuella Borg, 1933, preoccupied), 

 the latter having the autozoids often forming small clusters instead of 

 being more regularly distributed. One species of this genus forms a 

 heavy incrustation without any erect branches. 



Genus HETEROPORA Blainville, 1830 



"The zoarium is erect, arborescent, its surface smooth or slightly 

 rugose, honeycomb-like when the cystids are open ; the kenozoids much 

 more numerous than the autozoids, located between them and thus 

 separating them, aperture circular or polygonal." (Borg, 1944:210). 

 Genotype, Ceriopora cryptopora Goldfuss, 1827. 



Robertson (1910:258) gave a very clear statement of certain zoarial 

 details: "If one examines the growing tips of a branch, the tubular open- 

 ings found there are for the most part those of zooecia in various stages 

 of maturity. Between them, formed by minute triangular spaces where 

 the walls of zooecia do not come into contact, are the interstitial spaces 

 (kenozooecia). As growth proceeds, both zooecia and interstitial canals 



