ALCYONIDIUM ELEOANS. 59 



(d). Internally, the digestive sacculus presents eight longitudinal 

 lines, and a multitude of minute transverse folds. Its inferior termina- 

 tion becomes suddenly contracted, as though the terminal orifice were 



Fig. 25. 



Alcyonidiitm elegans (after Milne-Edwards, Ann. des Sc. Nat. 1835, pi. 12. fig. 1). a, foreign 

 body to which the polyp is attached; 6, the hard portion, or coriaceous foot; c, the trunk, or mem- 

 branous portion of the polypary; d, polypiferous ramifications of ditto; e, the soft parts of the 

 trunk completely retracted into the coriaceous stem ; f, yellow specks indicating the OTO, contained 

 in the lower portion of the polypary. 



closed by a sphincter muscle, and communicates with the wide abdominal 

 cavity (e) that occupies the entire diameter of the lower portion of the 

 polyp, and is prolonged inferiorly into the common body of the polypary. 

 The calibre of the digestive tube is much smaller than that of the 

 animal in the centre of which it is suspended ; nevertheless it is firmly 

 connected with the parietes of the polyp by the intervention of 

 eight delicate membranous lamellae derived from its outer surface 

 (fig. 26, 1 & 2, /) and extending along its whole length. The position 

 of these septa corresponds with the intertentacular spaces ; and as by 

 their upper extremities they are united to the peristomal disk, they 

 form the walls of eight longitudinal canals which are uninterruptedly 

 continuous with the cavities of the corresponding tentacula (fig. 26, 1, g). 

 These last-mentioned appendages are completely hollow, and moreover 

 present on each side of their internal cavity a series of ten or twelve 

 minute apertures (fig. 26, g'} leading into the marginal pinnules, that are 

 of similar structure. 



(127.) Inferiorly, the eight longitudinal interseptal canals communi- 



