124 THE VOYAGE OF H.M.S. CHALLENGER. 



Most species of the genus Cerianthus are far surpassed in size by Cerianthus ameri- 

 canus, which Verrill only has hitherto described. His account of it is as follows : 

 " Column very long, cylindrical, expanded at the top, tapering gradually below ; in 

 expansion, often two feet or more long, in contraction, six or eight inches. Body enclosed 

 in a loosely investing tube, buried in the mud. Tentacles long and numerous, the outer 

 series (125 or more) are from 1-25 to 1"50 inches long, slender, very flexile, usually 

 much curled at the ends; inner series similar, about 75 long, nearly the same as the 

 former in appearance ; often brought together and spirally twisted in a central bundle. 

 Base with a small but distinct opening. 



"Color of column dark cinnamon-brown, lined longitudinally with a lighter tint of 

 the same ; outer tentacles cinnamon-brown, lighter at the bases ; inner series darker, 

 marked with white longitudinal lines ; disk bright yellow, the central portion brown ; at 

 the bases of the tentacles spotted with dark brown." 



I consider the single specimen of the genus Cerianthus dredged by the Challenger as 

 identical with Cerianthus americanus. As it is more than 12 cm. long, it may easily 

 have measured more than 50 cm. when alive. The number of the outer tentacles, which 

 I reckoned at about two hundred, is larger than in the specimens examined by Verrill, 

 whilst their length is about the same. The distribution of colour on the tentacles was no 

 longer recognisable, as the whole colour of the animal had been changed by the spirit. I 

 did not attempt an anatomical examination, as I did not wish to destroy the unique 

 specimen. 



