TUBULARIA INDIVISA. 101 



we have already laid before the reader. It consists 

 of a central pouch or stomach, the orifice of which is 

 surrounded with a double row of tentacula, varying 

 in number from fifteen to thirty-five in each row, 

 while interposed between these two rows of larger and 

 of lesser feelers, and apparently originating from the 

 external lower part of the polyp, are seen the ovaria, 

 resembling minute protuberances at their first ap- 

 pearance, but forming pendent clusters on reaching 

 maturity. 



The tallest specimens sometimes rise as much as 

 thirteen inches high, and the stalks are about a line 

 in diameter where thickest, but the height and dia- 

 meter, the general luxuriance and the fertility of the 

 zoophyte, have no reciprocal dependence on each other. 



The Tubularia indivisa is generally found on shells, 

 entire or decayed, empty or tenanted, and sometimes, 

 in the latter case, a brilliant group may be met with, 

 carried along in its course by the crawling inhabitant. 

 As few vegetate on stones, the calcareous matter of 

 shells may possibly be more favourable to their evo- 

 lution. 



When the polyp or " head " of the Tubularia has at- 

 tained complete maturity, the tentacula become much 

 curved, their wonted regularity is impaired, and their 

 extremities indicate approaching decay. The pendent 

 ovarian clusters spread luxuriantly over them ; the cen- 

 tral pouch, as if its faculties were exhausted, is empty 

 and contracted the whole betrays a languishing and 

 sickly aspect. Next, a point of intersection may be 

 discovered amidst the ruddy pith near the summit of 

 the stalk, and the flower-like polyp, separating at this 



