ANTARCTIC BRYOZOA — ROGICK 265 



porous. A prominent ledge (bl of pi, 15,G) juts out from the back 

 wall where the ovicell joins its zooecium. This back ledge arises from 

 the end wall region of the zoid behind the ovicell (pi. 15,G). This 

 condition obtains for other species of this genus also (pis. 12,D; 14,K; 

 17,C,F). The ovicells are globular. Their dimensions, from broken 

 colony fragments and based on three readings only: length 0.346- 

 0.360 mm. (average 0.350 mm.); width 0.331 mm. 



Types: Holotype, USNM 11235; paratypes, USNM 11236. 



Ecology: This species was collected at Antarctic Stations 44, 45, 

 and 104. Also growing on the colonies were a worm tube and a 

 cyclostomatous bryozoan. 



Cellarinella roydsi, new species 



Plates 16,J,K; 17,A-I 



Diagnosis: Zoarium a heavily calcified, nodulated, flattened, 

 bilaminate slab. Shape flabellate. Branching dichotomous. Two 

 mucros below the orifice cradle an external avicularium which is 

 transversely placed across the front of the zooecium from the midline 

 outward. Mucros in front of and below the orifice, lateral, not median, 

 to it. Internal avicularium obliquely oriented and placed high enough 

 so its strongly curved beak shows in the orifice, from the outside. The 

 diagonally directed frontal oral ledge also shows from the outside. 



The species is named after its collection site. Cape Royds, Ross 

 Island. 



Zoarium: Eight good-sized chunks (as in pi. 16,J,K,) ranging 

 from 29 to 54 mm. in height, from 5 to 37 mm. in width, and from 

 IK to about 2)4 mm. in thickness, were in the collection. There were 

 also a few smaller fragments. 



The colony is ivory-colored, nodulated. Nodes are approximately 

 one-half to 1 mm. long, internodes 2 to 10 mm. long. The number 

 of rows of zooecia across the face of an internode, from one side edge 

 to the other, is about 20 to 88. The number of rows of zooecia along 

 an internode (longitudinally), from one node to the next, is about 

 6 to 14. 



Rootlets are present on some of the fragments. They sometimes 

 branch. 



The zoarium is bilaminate and flattened, with most of the zooecia 

 opening out on the two faces and a few on the edges also. 



Zooecia: Zooecial boundaries are not definable externally. Ex- 

 ternal measurements, taken from orifice to orifice in the same linear 

 series, gave approximate lengths of 1.008 to 1.944 mm. (average 

 1.513 mm.). Zooecial width, based on inside measurements, 0.302- 

 0.576 mm. (average 0,383 mm.). Zooecial thickness (distance from 



