Mr. Patterson on the Cydippe Pomiformis. 99 



assuming new aspects, being retracted either separately or together, and thrown 

 out in the same diversified manner. It is scarcely possible to convey, by any 

 description, an idea of the beauty and diversity of their forms. They seem 

 endued with exquisite sensibility, which, however, is not always equally delicate. 

 At times the slightest touch will cause a tentaculum to be drawn back into its 

 tube, with a sudden jerk ; at other times it is apparently unfelt. The Beroes 

 never seemed poised, or supported in the water by their tentacula. In one 

 instance, however, they were extended to the bottom of the vessel, where they 

 seemed to act as suckers, and formed fixed points, whence the animal rose and 

 fell at pleasure, and appeared as if moored by these delicate and novel cables, the 

 mouth being retained in the usual erect position. 



What are the functions of these singular organs, is a natural inquiry. My 

 friend, Robert Ball, Esq. of Dublin, states, that he regards them as organs of 

 prehension. This is the view taken by Blainville, when he speaks of them as 

 " servant pour attirer vers la bouche la proie qui s'y est attachee, probablement 

 par une matiere glutineuse."* Though unable to offer any more plausible con- 

 jecture, I cannot consider this opinion correct, as applied to the present species, 

 as during all my observations I have never seen them thus employed, and 

 from the comparative proximity of the orifices whence they issue to the anal 

 extremity, the tentacula float behind the animal, and never approach the mouth, 

 except at those times when the Beroe permits itself gradually to sink without 

 reversing its previous position in the water. 



" The mouth and oesophagus," as Dr. Grant remarks, " are wide ; and the 

 latter continues so to the stomach, which extends to the centre of the body. 

 * * * There are four prominent membranous lobes placed around the mouth, 

 which the animal can retract at pleasure." In the present species the appear- 

 ance of four lobes arises from two membranous plates, which unite along their 

 edges at either side, and are capable of being extended, so as to inclose an almost 

 circular space. In general, however, they are so nearly together that they pre- 

 sent very different appearances in different positions. The upper edge of each 

 membrane is divided into two semi-circular lobes, and these are constantly vary- 



• Manuel, p. 151. 



o 2 



