554 ZOOPHYTA. NUDA. Hydra. 



Height about an inch, transparent, brownish, or greenish, and consisting 

 of a o-elatinous matter, interspersed with minute granular glands. The body 

 is tubular, and open at both ends ; simple or branched ; tentacula varying 

 in number or height. The food, consisting of small annulose animals, is 

 seized by the tentacula, and conveyed to the alimentary canal, whence, after 

 digestion, it is ejected by the mouth. The absorbed nourishment is dispersed 

 through the glands even to the tentacula. The animal displaces itself and 

 creeps like a leech by the help of its mouth and tail, and even suspends it- 

 self from the surface of the water by its tail, which it expands like a funnel 

 for the purpose. The reproduction of this singular being, by buds, issuing 

 from the sides of the parent polype, acquiring tentacula, and then falling off 

 and becoming independent individuals, or by the regeneration of parts when 

 artificially divided, has long engaged the attention of the curious observer. 

 The animals may easily be procured by placing a quantity of the stems of 

 plants growing under water in any slow running ditch, in a basin of clean 

 water ; and in a short time the polypi will expand, and exhibit themselves 

 readily to the naked eye. 



** Inhabiting the Sea. 



208. H. lutea. — Branched, ovate, truncated, with about ten 

 short tentacula. 



Lamarck, Hist. ii. GO — On fuci, Belfast, Mr Templeton. 

 Height upwards of half an inch, stem narrow, head much enlarged ; ten- 

 tacula thick, not equal in length to the breadth of the body. The above de- 

 scription is from the drawing of an animal communicated to me by the late 

 Mr Templeton. 



209. H. coronata. — Body slender, head suborbicular, trun- 

 cated, with a flat disc; the tentacula issuing at the margin 

 from sheaths which radiate from the centre. 



Ellis, Cor. t. xxxviii. f. 5. — On Plumularia falcata. 

 Mr Ellis has given a figure of this animal, which does not seem to have 

 attracted the notice of subsequent observers. He states that it was of a red 

 colour, and that the tentacula " issued out of their sheaths like a star- 

 flower."— The true place in the system, of this and the preceding species, re- 

 mains to be determined. 



FacUius mirari el comment a ri quam vera dignoscerc et dejinire. 



