135 



an annulated animal, rather than that of a zoophyte, though 

 I have not succeeded in detecting it. 



LIMNIA DES. 



Polypidoms fleshy, or spongy, or corneous, polymorphous ; 



the polypes plaeed in tubes with angular or round orifices, 



closed when the animals recede. 



F RE DERI CELL A. 



Generic Character'. Polypidom fixed, coriaceous, tubular, 

 branched. Polypes issuing from the extremities of the 

 branches ; tentacular disc orbicular, tentacula arranged on 

 the margin of the disc in a single scries, about twenty 

 four in number, invested at their origin by a membrane. 

 Dr. Allman, Ann. and Mag. Nat. Hist., vol. 13, p. 331. 



FREDERICELLA SULTANA. Horny, trailing, sparingly 

 branched ; branches tubular, closed at their terminations 

 when the polype is withdrawn. 



Plumatella sultana, Johnston's Brit. Zooph., p. 323. 



Hab. On the weeds in the ponds at Trengwainton, near 

 Penzance; common. 



This species till very lately, was arranged with Plumatella, 

 but that genus is now divided into two, Plumatella, and 

 Fredericella by Allman and others. 



It is horny, tubular, creeping, and rarely exceeds an inch 

 in length. The branches are few in number, short and 

 sometimes dichotomously dividing. When the animal is 

 withdrawn, the openings of the tubes are closed. When 

 the animal protrudes itself, the openings become patulous. 

 The tentacula are about thirty, long, slender, though not of 

 equal length, and ciliated. The interior third of tentacula 

 and external surface of the mouth cloated with long cilia 

 which point towards the termination of tentacula, these do 

 not move in a vibratory manner, but are sometimes closely 

 applied to the surface and at others hang loosely. The 

 gizzard and intestine very visible. 



