Polyzoa of Mauritius. 73 



Most of the forms described below were fragments incrust- 

 ing the stem of a k\rge Gorgonia\ several specimens in- 

 crusted pieces of rock. 



Tills small collection is remarlcable for the large proportion 

 of what seem to be new forms. Out of 36 species 2f'i 

 appear to be new. 



Family Bicellariidse. 



DiPLCECiUMj nov. gen. 



Zoariura dicliotomous. Zooecia in pairs back to back, each 

 pair at right angles to those above and below ; the pairs 

 separated by short cylindrical corneous internodes ; orifice ol 

 cell with notch in lower border. 



Diplcecium shnplex^ n. sp. (PI. Vll. fig. 1.) 



Zooecia semitransparent, marked with a mosaic pattern; 

 each pair, viewed laterally, forming a triangle (with the 

 angles truncate) ; orifice suborbicular, with a rounded notch 

 below; peristome not raised ; no avicularia. Ooecia depressed, 

 flattened. 



In some parts of the branches the internodes are suppressed; 

 but the general arrangement of the zooecia is as described 

 above. 



Jt is doubtful in what family Diplcecium simplex should be 

 placed. 1 have placed it in the Bicellariida3 merely pro- 

 visionally. 



Family Cellulariidae. 



Genus Scrupocellaria. 



Scrupocellaria iniuuta, n. sp. (PI. IX. fig. 3.) 



Zoarium very slender, branched dichotomously. Zooecia 

 small, oblong ; area occupying i of cell ; spines 4 on outer 

 side, 2 on inner, operculum tan-shaped, entire ; lateral avi- 

 cularia large in comparison with cell, curved at apex ; no 

 anterior avicularia ; vibracular cells vertical, with short vibra- 

 cula ; radical fibres simple (not hooked). Uoscia? 



Genus Nellia. 



Nellia simplex^ Busk. (PL IX. fig. 4.) 



Nellia simplex, Busk, B. M. 0. p. 19, pi. Ixv. j 'Chall.' Rep. p. 27, 

 pi. V. tig. (3. 



The Mauritius specimen is in some parts crowded with 

 ooecia, which I have not seen figured or described. The 



