1910] Robertson: Cyclostomatous Bryozoa. 257 



angles to the column. Zooecia relatively few in number, 

 frequently but four, projecting in four directions at any given 

 level of the stalk or branch. Oacia unknown. 



The colonies here described are simple and unbranched. No 

 ovicells are found, this and their lack of branches being per- 

 haps due to their youth. 



E. run in i in w:is obtained at Monterey, California, in 90 fathoms. 



100. Entalophora capitata Robertson. 



PI. 24. figs. 44, 45. 



Entalophora capitata Robertson, 1900, vol. 2, p. 328, pi. XXI, fig. 12, 

 not 11, 13. 



Zoarium arising from a flattened or incrusting base and 

 growing from 5 to 6 or 8 mm. in height (pi. 24. fig. 44). Zocecia 

 tubular, uniting in a short, stout column terminating in a broad 

 somewhat rounded head; distal ends free, usually extending for 

 a considerable distance beyond the general surface of the colony, 

 both of the supporting column and of the head. Oascium an 

 inflation of the surface of the head (fig. 45, oe.) Oozciostome 

 and ooeciopori coinciding (ocp.), slightly compressed, opening 

 beside the zocecial aperture. 



E. capitata obtained on shore rocks at Orea, Prince Williams Sound, 

 Alaska, at low tide ; also dredged at Juneau, Alaska, in 10 fathoms. 



Heteropora Blainville. 



Heteropora Blainville, 1834. 



Heteropora, Lonsdale, 1845. 



Heteropora, Busk, 1859. 



Heteropora, Waters, 1879. 



Heteropora, Busk, 1879. 



Heteropora, Whiteaves, 1882. 



Zoarium erect, branching. Branches cylindrical, in well- 

 grown colonies frequently anastomosing; surface furnished with 

 openings of two sizes, the larger being the orifices of zocecia. the 

 smaller, the openings of the interstitial canals or tubes. 



According to Busk (79) Heteropora is an ancient genus 

 well known among fossil Bryozoa as far back as the Cretaceous. 

 The characteristic feature of this genus, as the name indicates, 



