128 



RET. T. HINCKS OIT POLYZOA 



tively large, and from the suberect habit of the cell, the ventral 

 aperture, extending from the bottom (or nearly so) to the top, is 

 more apparent and more readily studied (Plate XII. fig. 9). The 

 solid or chitinous portion of the zocecium forms a kind of 

 carapace closed in below by a membranous wall. The polypide 

 stretches along the upper portion of the cell immediately beneath 

 the chitinous shell and issues at the top of the oral area. The 

 structure, so far as it can be determined in spirit-specimens, is 

 extremely simple ; there seems to be no trace of a gizzard. In 

 the setose portion of the tentacular sheath there is an interesting 

 peculiarity. The setse before expanding, instead of being 

 packed together so as to form a straight pencil, are seen to be 

 subspirally arranged, some tending to one side, some to the 

 other, and bear some resemblance to loosely twisted strands in 

 a cord. As the tentacular corona moves upward and presses 

 upon the base of the operculum, the setse disentangle themselves 

 and expand into the usual funnel-shaped figure. The setse with 

 the reversible portion of the sheath from which they rise equal 

 the cell in length. The four setose appendages placed round 

 the upper portion of the cell-margin form a very conspicuous 

 and striking feature. When the polypide is exserted, they are 

 thrown back and stand out from the cell; when it withdraws 

 they are brought together and project at the summit. 



The tubular adherent processes given off" from the lower part 

 of the cell correspond to the spines round the base of the 

 zocecium in B. nitens. The cells are developed in large numbers 

 on the creeping stem, and the growth is luxuriant. 



Family CylindikeciiDjE. 



Cylindr(Ecium, Hincks. 

 Cylindrcecium oiganteum, Busk. 



I can detect no difference between the Mergui form and our 

 British species. 



I I ah. On Nellia oculata, J3usk. 



English roast; Adriatic; Bay of Naples; Queen Charlotte 

 Islands, North Pacific.] 



