SEA-MA T MAKERS. 301 



one of the latter was cut off from a cell, the lower 

 mandible retained its power of opening and closing. 

 Perhaps the most singular part of their structure is, 

 that when there were more rows of cells than two, 

 the central cells were furnished with these appen- 

 dages, of only one-fourth the size of the lateral ones. 

 Their movements varied according to the species ; 

 in some I never saw the least motion ; while others, 

 with the lower mandible generally wide open, oscil- 

 lated backwards and forwards, at the rate of about 

 five seconds each turn ; others moved rapidly and 

 by starts. When touched with a needle the beak 

 generally seized the point so firmly, that the whole 

 branch might be shaken. 



" These bodies have no relation whatever with the 

 production of the gemmules. I could not trace any 

 connexion between them and the polyp. From 

 their formation being completed before that of the 

 latter ; from the independence of their movements ; 

 from the difference of their size in different parts of 

 the branch : I have little doubt that in their functions 

 they are related rather to the axis than to any of the 

 polyps." 



He then proceeds to notice another kind of struc- 

 ture which is analogous to the vulture-heads, and 

 which some naturalists consider to be only a form or 

 modification of 4 the " bird's-head processes." He pro- 

 ceeds : " A small and elegant species is furnished, 



