I ANTARCTIC BRYOZOA — ROGICK 293 



Zooecia: The more or less hexagonal zooecia are rather heavy- 

 bodied, i. e., thick-walled. A faintly raised mural rim outlines the 

 gently convex frontal wall. Where the frontal wall bulges more 

 prominently, the mural rims lose their salient appearance and slope 

 gradually down to meet the walls of the neighboring zoids, thus 

 forming a "valley" between zoids. The frontal wall is punctured by 

 numerous, evenly spaced pores set closely together everywhere except 

 in the peristomial region. The slightly beaded peristome rises 

 above the rest of the frontal, flaring outward and interrupted or 

 straddled by the peristomial or oral avicularium. 



Avicularium: Only one type — the medium-sized, peristomial, 

 spatulate type— occurs. It is always present and in the same loca- 

 tion, set in the middle of the peristomial proximal rim. The spatu- 

 late mandibular section is larger and bent at the pivot or cross bar 

 in a different plane than the smaller subhemispherical back avicu- 

 larial area (pi. 26,A,E,G). The spatulate mandible has a basal 

 and peripheral chitin reinforcement (pi. 26, G). The avicularial 

 chamber is placed between the lyriila and the peristome. The two 

 planes of the avicularial surface (the mandibular and back areas) 

 are both at varying slants with respect to the plane of the zooecial 

 frontal, so the avicularial sm'face is bent or bevelled. 



Orifice: The primary orifice is well hidden by the projecting 

 peristome and avicularium. It has a low, medium-wide lyrula and 

 cardelles (pi. 26,B). The peristomie or passageway between the 

 primary and secondary orifices is long and somewhat reniform on 

 end because of the avicularial chamber. The proximal half of the 

 peristome often appears slightly wider than the distal half. The side 

 walls sometimes pinch inward medially to give the secondary orifice 

 an almost trifoliate appearance. The distal peristome wall is made 

 up largely from the wall of the next zoid in the series (pi. 26, A,B). 

 In ovicelled zoids the lateral peristome walls grow upward onto the 

 sides of the ovicell. No opercula were found. 



Ovicell: Few ovicells are in the colonies. They are globose, 

 salient, smooth frontaUy, and punctured by about 16 casually dis- 

 tributed elliptical or oval pores over the thin smooth frontal area. 

 The periphery of the ovicell is a bit thicker, rougher and crusty. 



Distribution and ecology: The holotype (USNM 11314) is 

 from Station 45 and consists of a scrap of about three dozen zoids, 

 some overlapping others, growing around a stalk of "Smittia" inclusa 

 Waters 1904 {= Clithriellum inclusum). The paratypes consist of 

 more zoids encrusting other Bryozoa (a retepore, Mucronella croze" 

 tensis, and Smittina abditamcularis) from Station 44. No soft poly- 

 pide parts are in the specimens. 



