26 W. G. KIDEWOOD. 



on the plume-axes and on the pinnules, but they occur in greatest abundance in the 

 dorsal layer of the buccal shield. 



The red colour of the curved line of the buccal shield and that occurring in 

 the oviducts is due to closely crowded granular cells of small size, of uniform 

 character, and of a bright red colour which remains, or, at most, has turned to a 

 reddish brown, in sections cut by the paraffin method. In the material fixed by 

 picric acid solution the cells are not swollen, but present the same appearance as 

 in that fixed by formalin or by Perenyi's fluid. 



Except in the case of a small number of polypides found loose at the bottom 

 of the bottles specimens which had clearly escaped from their tubes at the 

 moment of immersion of the colony in the preservative fluid (fig. 14, plate 4) and in 

 polypides taken from the terminal tubes of the colony (fig. 15), the stolon does 

 not stand out obliquely or hang ventrally as it does in Cephalodiscus dodecalophus, 

 but it runs back parallel with the long axis of the body (figs. 7 and 8, plate 3). On an 

 average of cases it leaves the body midway between the hind edge of the buccal 

 shield and the end of the visceral mass. It is short, stout, and transversely 

 wrinkled : in much contracted specimens the visceral mass partially envelopes the 

 stolon, a concavo-convex flap of it lying against one or both sides of the stolon. 

 On the other hand, in the above-mentioned individuals which appear to have died 

 free, and uninfluenced by the limitations imposed by the tubes (fig. 14), the 

 visceral mass is not distorted by the stolon, and, further, it has a general curva- 

 ture towards the ventral side of the body. 



There is. a striking uniformity in the general appearance of the fully -grown 

 individuals. Full-grown polypides that have not two or more buds and a pair of 

 gonads in mature condition are not met with, and the regular presence of ripe 

 gonads in individuals which are actively budding is not the least remarkable feature 

 of Cephalodiscus. Further, although large ova are frequently encountered lying 

 loose and singly in the blind ends of the tubes of the colony, they appear to be 

 all of the same age, and exhibit no signs of segmentation. 



A polypide remains as a bud until its plumes are almost of full size, and 

 until itself is nearly as large as the individual to the end of whose stolon it is 

 attached. Such a " ripe " bud usually carries at its point of contact with the main 

 stolon a very small bud of its own, and it has gonads about one-fourth or 

 one-third of the normal size. 



Although throughout the colony, and not merely at the apices, the polypides 

 are producing buds, it is only at the tips of the branches that one meets with what 

 may be regarded as newly established polypides. A polypide from one of the 

 terminal tubes of a branch of the colony differs from ordinary polypides, in that 

 there are no gonads recognisable by dissection,* the visceral mass is more swollen 



* This is odd, in view of the fact that small gonads can be recognised in ripe buds not yet separated from the 

 parent stolon. 



