III. FAMILY SCLERODOMIDAE 



Plates 12-18 



The six species discussed in this study belong to the family Sclero- 

 domidae Levinsen, 1909, genus Cellarinella. The genus has been 

 reported by only four authors to date and all specimens have been 

 from Antarctic collections. This article adds six new Antarctic 

 species. The four previously known species did not occur in the col- 

 lection of the U. S. Navy's 1947-48 expedition. 



Taxonomy and morphology: Vigneaux (1949, pp. 17, 23) has in- 

 troduced a much-needed reclassification of families and genera which 

 would require critical study of a number of related species that time 

 idoes not permit at present. He erected a new family, Lepraliellidae, 

 to accommodate Cellarinella. However, Levinsen's classification, 

 although not perfect yet, is based on very scholarly and thorough 

 morphological studies and it is followed for the present. 



Characteristics of the family are discussed in detail by Levinsen in 

 his monograph (1909, pp. 301-304). He stated (p. 301): "The very 

 small distal wall is provided with a number of small uniporous rosette 

 plates and the lateral walls with a varying number of rosette plates with 

 few (two or three) pores. There is a membranous or weakly chitinized 

 operculum and a more or less well developed peristome ..." 



On the basis of the material examined in the 1947-48 collection the 

 following amendments or modifications of his family diagnosis can be 

 made. First, his "distal wall" is the end wall which separates one 

 zooecium from the next one in the same linear series. It could be 

 called the proximal wall or the distal wall, depending upon one's point 

 of view or if describing the walls of a single zooecium. At any rate, 

 this distal-proximal waU may consist of a sieve plate, i. e., a plate or 

 wall containing a number of small pores (pis. 12,I,J; 13, C; 14,K; 

 15,F,G; 16,F; 17,F). Second, the rosette plates or pore plates of 

 the lateral walls may sometimes contain more than two or three pores 

 (pis. 12,1; 15,G,H; 17, C). Third, an operculum could not be found 

 in any of the material. 



Genus Cellarinella Waters, 1904 



Zoarium calcareous, "nodulated," ranging from spindly or slender 

 sprigs to heavy, flattened, fan-shaped bilaminate slabs. Branching 

 sparse and dichotomous. Stalks elliptical to flattened strips in cross 

 section, with zooecia opening on all faces. OviceUs hyperstomial. 



350640—56 3 253 



