135 



an annulated animal, rather than that of a zoopb^te, though 

 I have not succeeded in detecting it. 



LIMNIADES. 



Polypidoms fleshy, or spongy, or corneoas, polymorphous ; 



the polypes placed in tubes with angular or round orificea, 



closed when the animals recede. 



FREDERICELLA. 



Generic Character: Polypidom fixed, coriaceous, tubular, 

 branched. Polypes issuing from the extremilies of the 

 branches; tentacular disc orbicular, tentacula arranged on 

 tbe margin of the disc in a single series, about twenty 

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

 Dr. Allraan, 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 when the polype is withdrawn.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 lliat 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. Tlie branches are few in number, short and 

 sometimes dichotomously dividing. When the animal is 

 withdrawn, the openings of the tubes are closed. Wiiea 

 tbe animal protrudes itself, the openings become patulous. 

 Tlie tentacula are about thirl), long, slender, though not of 

 equal length, and ciliated. The iulerior 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. 



