ANTARCTIC BRYOZOA — ROGICK 239 



biaterial. The distal edge of the operculum is nearly straight to 

 gently convex, the two lateral sides are nearly parallel and the proxi- 

 mal border is slightly concave. Two short, obliquely set sclerites are 

 placed a short distance from the lateral walls. The operculum seems 

 to have a chitinous flange that fits inside the orifice. 



The orifice itself seems to be very much like that of the other 

 species in this genus. It is nearly straight distally, its two lateral 

 sides are almost parallel, and its proximal border is concave and 

 bordered by a curved lip. The two proximal condyles are visible 

 sometimes through the operculum. The distal teeth may be present 

 although they were not clearly seen. The orifice of this species is 

 not raised quite as much from the frontal zooecial surface as are those 

 of other species in this genus. The orifice is located about its own 

 'length away from the distal arch or cornice. 



OviCELLs: The ovicells are placed between the orifice and 

 the distal cornice, occupying the whole area and sometimes 

 extending beyond but under the cornice, to fit partly between and 

 'beneath the side walls of the distal zoids. The ovicell shapes vary 

 from a very broad oval to a rounded-corner triangle. The exposed 

 ovicell wall in some cases is tubercled, as is the cr3rptocyst. The side 

 'walls of the ovicell begin at the distal corners of the zooecial orifice, 

 meeting the ends of the cryptocyst ridges. The ovicell side walls are 

 salient but not highly so. They meet the extended corners of the side 

 walls of the zoid to form the distal cornice of the individual. The 

 dimensions of the ovicells are: length from 0.101 to 0.137 mm. 

 (average 0.115 mm.); width 0.173 to 0.202 mm. (average 0.179 mm.). 



Avicularia: None was seen on the small sprig. 



Radicles: The chitinous rootlets sprout from the midfrontal face 

 as in the other species of this genus, and grow in a downward (prox- 

 imal) direction, toward the base of the colony. Their diameter is 

 0.050 to 0.072 mm. (average 0.067 mm.). 



Type: Holotype, USNM 11219. 



Ecology: This species occurred at Antarctic Station 104. No 

 other species of animals were growing on the single sprig. 



Cellariaeforma extentamuralis, new species 



Plates 7,1; 8,A,B 



Diagnosis: Characters same as those of the genus, plus the follow- 

 ing features. Areolation and external faces of the zooecia rhombic to 

 hexagonal. Areolation heavy, coarse, visible to the naked eye. 

 Zooecia arranged in transverse series of sLx or seven around the longi- 

 tudinal axis of the branch. Cryptocyst not tuberculate. Zooecial 

 side walls flare outward obliquely very conspicuously above the general 



