14 



The stalks of the zooids of C. sibo^ae are excessively long and slender (as in C. gracilis). 

 It seems to me by no means impossible that they may be sufficiently extensible to permit of 

 the protrusion of the tentacles from the orifices while the bases of the stalks still remain in 

 the basal encrustation. However this may be, it cannot be doubted that the densely massed 

 zooids found in the basal jiart of this colony possessed during life the power of entering the 

 erect tubes. 



The tubes may be simple, bifurcated, or somewhat more branched. In one case which 

 I have noticed, the tube trifurcated near its ba.se, and two of these branches bifurcated a 

 little later, making five branches in all. The branches have a certain straightness, which is 

 in contrast with the sinuous and decumbent branches of C. gracilis., and is correlated with a 

 firmer consistency of the jell\'. Their colour is definitely orange (in spirit), those of C. gracilis 

 having so little of the orange colour as to a])pear almost colourless. While the basal encrustation 

 is for the most part free from foreign inclusions, all parts of the erect tubes take up an 

 enormous number of particles of detritus or mud (which may possibly be faecal), as well as 

 bodies such as the shells of Foraminifera and sponge-spicules. 



The orifices are typically wide funnels which ]:)roject from the walls of the tube, and have 

 a tendency to assume an alternate arrangement. The peristomial filaments are stiffer and sliorler 

 than in C. gracilis. The lamellae whicli constitute the greater part of the tube are readily seen 

 without .staining. The upper half of l*"ig. i 7 shews that they are convex distally and that they 

 are of small size, a feature which may be regarded as correlated with the small size of the 

 proboscis in this species. They are in fact not large enough to form even one half of the 

 transverse circumference of the tube. 



In C. gracilis (Fig. 16) on the contrary, the lamination is more difficult to make out 

 without staining. The lamellae are not specially convex distally, and their arrangement recalls 

 that found in C. levinseni, a tendency towards an oblicpie arrangement being noticeable, while 

 the lamellae in many cases .stretch across the whole of one of the lateral surfaces of the tube. 



The mode of growth of the coenoecium of C sidos'ac resembles that found in C. (gracilis. 

 The lower part of fig. 17 shews a funnel-shaped expansion, which was formerly the terminal 

 orifice of the tube, its lower lip being still indicated by a prominent line a. This orifice was 

 |jrovided with the three peristomial processes d, c, and d, of which d lies in the wall which is 

 furthest from the observer. W ith the prolongation of the wall of the tube by the deposition of 

 fresh lamellae, the funnel-shaped orifice became narrowed, jiart of it remaining as an orifice c, 

 in relation with the process <5, the rest of it extending as a separate orifice along the process d. 

 The process c thus became removed from any connexion with an orifice, and so ceased to 

 grow. The process d, which in the lower part of the figure lies in the deeper wall of the tube, 

 and in the upper part becomes nearly lateral, constitutes the principal skeleton of the tube, and 

 is continued beyond its terminal orifice i as the process n. When the tube had reached a 

 certain distance, a new peristomial process iji) was formed, which has become the support of 

 the orifice /, most of which is concealed by the base of the process. The line g indicates the 

 margin of the terminal orifice at a previous stage, although a considerable part of this funnel 

 has now been closed by the onward growth of the tube, jjart of it persisting as the orifice /. 



