218 ZOOPHYTES. 



Plate XLI. Fig. 6. Prolific vesicle. Here the contents, as in others, are in 



a double row. 



7. Tintinnabulum or Medusa quitting the orifice of the vesicle. 



8. Tintinnabulum at large, reversed. 



9. Tintinnabulum in plane. 



, All the figures of this plate, except the first, are enlarged. 



§ 2. Sertularia (Campanularia) verticillata. — Plate XII. 

 Figs. 1-8. — Although the young of this product be sufficiently numerous 

 and easy to be obtained, nor of difficult preservation, its rarity as an 

 adult, in any places I have resorted to, forbid conjectures regarding both 

 the dimensions and the luxuriance which it may ultimately reach. 



For many years I "was induced to consider the species as consisting of 

 no more than a single hydra in its bell, sustained by a stem ; that in this 

 simple form it originated, flourished, and decayed. As such, it should 

 have attracted the notice of preceding naturalists, especially from its size, 

 being one of the largest camj^anulate hydrse in the Scotish Seas. 



In a better stage it has occurred to me as an erect stem, with one or 

 two subordinate branches, but nothing more. However, others have had 

 it in greater luxuriance. — PI. XII. fig. 1. 



This zoophyte rises above two inches high by a short stem, composed 

 of aggregated tubuli, and with an obtuse summit. Branches originate at 

 a large angle from the stem, bearing campanulate twigs and hydrse, in 

 sets of four, five, or six. The twig is faintly whirled, sometimes so in- 

 distinctly as to be scarcely perceptible ; and the bell is of excessive tenuity. 

 This is in the form of what is called a Chinese bell, having a plain or ser- 

 rate lip, for both are undoubtedly seen, without denoting a species obvi- 

 ously distinct. It may constitute a variety. 



The hydra rises within the bell to display above 30 muricate tenta- 

 cula. — Fig. 2. But when fully extended, these lose their muricate aspect 

 under the microscope, then resembling articulated organs with several 

 very short obtuse spinous processes from the origin of each articulation. 

 The animal seems to be capable of exercising some slight influence over 

 the twig. 



The inorganic parts are of faint greenish-yellow colour ; the hydra of 



