BRANCHIOCEEIANTHUS IMPERATOR (aLLMAn). 243 



canals on the higher side of the disc are not so long as those 

 on the lateral, bnt run straight from the base of the gonosomes 

 to the outer margin of the disc, the length of the canal being 

 thus the same as the breadth of this region (Woodcut 2). 



The radial canals and the intercalated cords increase in their 

 width towards the outer margin of the disc where the both struc- 

 tures are broadest. Inwards, the radial canals open into that part 

 of the hydranth-cavity where the cavities of the gonosomes stand 

 in communication with the latter. Outwards, the canals terminate 

 blindly on the margin of the disc. The intercalated cords 

 enlarge suddenly near the margin of the disc and acquire a 

 cavity which forms a part of that of the marginal tentacle (PL 

 XV, Fig. 1). 



The name of marginal tentacles [mi) is given to the outer- 

 most circle of filiform tentacles arranged like a fringe around the 

 margin of the disc. The circle is not complete, there being a 

 hiatus (v) at the lower edge of the disc where the surface of the 

 hypostome passes directly into that of the hydrocaulus. The 

 shortest tentacles arising from the 6th or 7th intercalated cord, 

 counting from the lower edge, occu^^y the two ends of this in- 

 complete ring. AVhether there were any smaller tentacles nearer 

 the lower edge, I am not sure. There is no indication, so far 

 as I can see, of any having existed. Towards the higher edge 

 of the disc they increase successively in length until about the 

 10th (counting from the lower edge) is reached, of which the 

 length on both sides is about 200 mm. After this there seems 

 to be no special arrangement of the tentacles, which vary from 

 200 mm. to 300 mm. in length. They numbered 198 in all. 

 The tentacles are flattened at their base, and are compressed so 

 closely with one another that the basal portion appears to form 



