Chatham Island and d' Urvilii Island. 13 



ringed structure ceases. The last few rings are broken up, 

 in the lower ones into long ridges, hut at each succeeding 

 ring into shorter oiu's, so that for a sliort dist.mrc the line 

 of rings can he distinctly traced, though ultimately the dots 

 seem to he irregularly plaeetl. 



The genus ^Etea rcijuircs elucidation on living or well- 

 preserved spi ciniens, as it has often heeu imperfectly unthr- 

 stood. Busk, Ilineks, and other authors have supposed that 

 the polypidc lived only in the oial tuljc, and regarded the 

 zoa?eiuni as merely a i)art uf ihe stolon. Smitt figured the 

 growth correctly, and 1 referred to the position of the 

 zooecium and gave a ligure in my paper on the Bryozoa of 

 Naples*; and JuUieu, overlooking what had heeu written, 

 again called attention to the mistake made by so many 

 authors. In many cases there seems to be but little room 

 for the polypitle in the zoffcium, so that then it may be 

 seldom or never entirely withdrawn, though in the specimen 

 figured by me fnun Naples the zooccial chamber is very 

 large and the polypide lias ample ruom. However, other 

 specimens have convinced me that, although ^E. recta occurs 

 from Naples, the one 1 figured is a new species which it is 

 proposed to call xE. lepadt/ormls, as the a])peiidagcs, which 

 are usually on very short ringed stalks, are somewhat similar 

 in shape to the head of Lepas. 



Hub. Arctic; Europe; Madeira; Australia; New Zealand ; 

 French Pass, d'Urville Island, New Zealand. 



Membranipora hiatis, Iliiieks. (PI. I. fig. 12.) 



Metnbrani}X)ra hians, Ilincks, Ann. Sc Mag. Nat. Ilist. ser. 6, vol. xv. 



p. 1^48, pi. vii. til,'. 5; Waters, Juurn. Linn. Soc, Zool. vol. xxvi. 



p. (W7. 

 Membranipora cyclops, Busk, Cat. Mar. Polyzoa, p. 61, pi. Ixv. fig. 3, 



Zoarium iinilaminatc ; area large, nearly round ; a broad 

 calcareous Avail between the zooecia, the wall is more or less 

 flat on the top, and upon it tlicre are small triangular 

 avicularia, which, although often appearing to be irregularly 

 placed, are really below the area ; usually two avicularia, 

 but sometimes only one. 



The operculum projecting beyond the ridge is charac- 

 teristic and has been figured by me {/uc. cit. fig. 1(5, pi. xlviii.). 



The specimen now described and figured is from the 

 maturer part of the colony, and we do not often find so solid 

 a calcareous growth between the zooecia; but Ilincks's 



♦ Ann. vt Mk^'. Xat. Hist. sit. o, vol. iij. j». 1 1 J, pi. xv. \\)Z. 7. 



