a remarkable Hydr Old Polype. 311 



young the greater part of the body is inclosed in a thin 

 brown membranous tube, which appears to have no organic 

 connection with the animal, and which growing thinner as 

 the animal gets older, at last disappears altogether. The 

 body or stem is rounded, solid, and flexible, and is somewhat 

 thicker towards the base than above, where it tapers rather 

 suddenly to the neck. The base is fusiform and tapering to 

 a point, and roots in the sand, fixing itself there by means 

 of branching filamentous roots. When sand is much ga- 

 thered round these roots, they present that subglobose ap- 

 pearance seen in M. Sars's figure. The whole of the stem is 

 translucent, of a white colour tinged with pink, and lineated 

 with pinkish-brown, longitudinal lines arranged in pairs. 

 When magnified these lines are seen to be composed of ob- 

 long dots. M. Sars described these stripes as being of a 

 pale vermilion colour in his specimens. These lines« do not 

 run down the fusiform root, neither do they extend upwards 

 quite to the neck, round which there is a band of pink. 

 Above the neck is the head, which is ovate or pyriform, and 

 terminates in a long pyramidal pink trunk, at the extremity 

 of which is the mouth. Round the thickest part of the head 

 is placed a row of between 40 and 50 tentacula, which are very 

 long, white, and not contractile. They are not ciliated. Im- 

 mediately above this circle of tentacula are the ovaries, which 

 are 14 branched orange-coloured processes of considerable 

 size, about one-third as long as the tentacula, each of their 

 branches terminating in a sort of head. Above these the 

 trunk is covered with very numerous white tentacula, directed 

 upwards, not contractile, and very much shorter than those 

 of the lower circle. 



The internal structure is as follows. The stem is entirely 

 solid, the substance filling it being jelly-like in appearance, 

 as if contained in cells of a slightly fibrous tissue. When a 

 transverse section of the stem is made in the living animal, 

 the outer membrane contracts so as to diminish the dimen- 

 sions of the amputated portion. No vascular structure could 

 be detected, on the most minute examination of transverse 

 and longitudinal sections of the stem ; nor could any current 

 be observed, either with the naked eye or the microscope, in 



