Royal Physical Society. 371 



to a new genus, for which I propose the name Ephelota (from 

 en-/ and faog, a peg, and its derivative adjective qXurog). 



The body of Ephelota apiculosa (Alder's first described 

 animal) is cup-shaped, set round with numerous pointed ten- 

 tacles, abruptly thickened towards the base, and forming more 

 than one row. They have very little motion, but are occa- 

 sionally bent forwards, and sometimes slowly retracted. Body 

 attached to a stout stem. In Mr Alder's figure the stem 

 appears of the same thickness throughout. I have occasion- 

 ally found an animal, which I believe to be identical with 

 Ephelota apiculosa, growing on Coryne. It differs from 

 Ephelota coronata (the animal I have figured, Plate XVIII. , 

 fig. 1), in having the body more cup-shaped, elongated, and 

 wider than the stem ; the tentacles more irregular, soft, retrac- 

 tile, and unsupported by the solid matter which occurs in the 

 interior of those of Ephelota coronata ; and, especially, in 

 the shape and structure of the stem, which is nearly of equal 

 diameter throughout, and consists of a medullary substance, 

 the fibres of which pass in a longitudinal direction, inclosed 

 within a cortical substance, formed of circular fibres, passing 

 at right angles to the fibres of the medulla — which cortical 

 fibres are absent in the stem of Ephelota coronata. 



I have found Ephelota coronata only twice, each time in 

 large colonies, situated within the mouth of shells inhabited 

 by the hermit crab, where the dense white bodies of the 

 animalcules, seated on their transparent pedicles, form suffi- 

 ciently remarkable objects. 



The body consists of a short cylinder of densely granular sar- 

 code, slightly enlarged above and below, so as to resemble the 

 circlet of a crown. It is surmounted by a circle of thick, acumi- 

 nate, and radiating tentacles,which are capable of being slowly 

 curved inward, but cannot be contracted. They remain stiffly 

 extended, even when the animal is immersed in alcohol. The 

 structure of the tentacles is, I believe, unique. Under high 

 microscopic power, they are each seen to consist of a bundle 

 or frame-work of fine parallel rods of horny (?) texture, em- 

 bedded in soft contractile sarcode. The more central rods of 

 the bundle (as in the figure 2) protrude continually beyond 

 those exterior to them, so that the point of the tentacle is 



