520 ALFRED C. HADDON. 



narrow tube still retaining its primitive connection with the 

 tentacular crown, to which it is attached about one third from 

 the base. 



While the changes described above have been taking place, 

 the tentacles have been gradually lengthening, at first, they 

 are short finger-like processes from the periphery of the lopho- 

 phore, closed above, open below, containing within their 

 cavities an extension of the original outer layer of the bud 

 which here forms an epithelial lining (PI. XXXVII, figs. 8 and 

 9, a, and also woodcut, fig. 1) ; not till comparatively late do 

 cilia arise on the outer epithelium, only certain aspects of the 

 surface of the tentacles are clothed with cilia (see PI. XXXVII, 

 fig. 9, a). 



The tentacular sheath ultimately becomes continuous with 

 that portion of the endocyst of the zooecium which surrounds 

 the mouth of the cell as was insisted upon by Nitsche (13, 

 p. 463). 



The retractor muscles of the body and lophophore arise, as 

 noticed by Repiachoff (15) from the peritoneal lining of the 

 polypide. 



The funiculus early becomes prominent and is probably 

 derived from the irregular strands of funicular tissue which 

 occur in the parent zooecium; it appears as a thickish cord 

 stretching from the fundus of the developing polypide to the 

 base of the zooecium, and, almost invariably, it is in direct 

 connection with the brown body, so that it serves to direct 

 the developing alimentary tract to that nutritive mass, thereby 

 ensuring the better nutrition of the growing bud. 



Abnormalities extremely rarely occur in which there may 

 be two buds developed, or more than one brown body, or the 

 polypide may not come into contact with the brown body. 

 The second abnormality probably being the result of the third. 

 It is thus clear that the bud in Flustra carbasea is deve- 

 loped at a distance from the brown body, that it approaches 

 the latter, envelopes it, and extracts nutriment therefrom. As 

 was pointed out by Repiachoff (10) the same occurs in several 

 genera of Polyzoa (Tendra, Lepralia, Membranipora, 



