I 



ANTARCTIC BRYOZOA — ROGICK 291 



)rdinata and S. alticollarita. Its curved distal third is formed by the 

 rontal wall of the next distal zoid. The other two sides may be 

 straight in young zoids, or curve inward in older zoids, depending upon 

 .he thickness of the growing, encroaching peristomial walls. The 

 jrimary orifice is smittinoid, wider than long, with a wide low lyrula 

 md fairly prominent cardelles that sometimes show and sometimes do 

 lot. Few opercula are present. Between the primary and secondary 

 )rifices is the small oral avicularium. 



Ovicell: The ovicells are globose, moderately salient and thick- 

 .valled. They are met at the sides by the heightening peristome (pi. 

 25,E). They are punctured by pores similar to those of the zooecial 

 iTont. The pores are over most of the ovicell surface, not restricted 

 to a central porous area that Busk (1884, p. 151) describes for S. 

 Bmittiana, a closely related species. The ovicell is comparatively 

 targe. 



Distribution and ecology: Only three fragments of partial 

 colonies are in the collection. A paratype from Station 226 measures 

 i by 7 mm. The holotype (USNM 11304) from Station 44 is growing 

 over a retepore, in close proximity to a colony of Smittina excertavic- 

 ulata. Another specimen from Station 44 is growing partly over 

 Microporella trinervis, which in turn is supported by other bryozoan 

 species (Smittina oblongata and the retepore). This patch measures 

 about 10 mm. by 36 mm. and represents the growing edges of possibly 

 two colonies. 



Affinities: This species resembles S*. smittiana Busk (1884, p. 151, 

 pi. 17, figs. 3,3a,3b) in the following ways: Both have a wide low 

 lyrula (some differences however) ; primary and secondary orifices of 

 both species agree; both have an oral avicularium enclosed within the 

 peristome; both have a tremocyst; and the zooecial width is the same 

 in both although the length of some of Busk's specimens appears to be 

 itwice that of mine. 



The two species differ in the following ways: Shape and relative 

 size of the oral avicularium; extent of perforation of the ovicell; and 

 occurrence of salient mural rims in S. canui, sometimes encroaching 

 upon or over the ovicell, but not in S. smittiana. 



Busk (1884, p. 151) gives an ambiguous account of the lyrula and 

 does not figure it. Canu and Bassler (1920, pp. 458-459, fig. 132m) 

 picture it but their figure also reveals an oral avicularium which is 

 proportionately much smaller with respect to the lyrula than is true for 

 S. canui. Busk describes the avicularium as round, but that of 

 S. canui is longer than wide. The avicularium figured by Canu and 

 Bassler also is longer than wide. In S. canui, the ovicell is perforated 

 all over, while in S. smittiana the perforations are restricted to a reni- 



