APPENDIX. 21 9 



Cellulaeia ciliata. pi I. fig. 7. 

 The cells are alternate on the stem, and are 

 curiously armed with long whip-like cilia or spines. 

 On the hack of some of the cells is a very strange 

 appendage, the use of which is not with certainty 

 ascertained. It is a minute body, slightly resembling 

 a vulture's head, with a moveable lower beak. The 

 whole head keeps up a nodding motion, and the 

 moveable beak occasionally opens widely, and then 

 suddenly snaps to with a jerk. It has been seen to 

 hold an animalcule between its jaws till the latter 

 has died, but it has no power to communicate the 

 prey to the polype in its cell or to swallow and 

 digest it on its own account. It is certainly not an 

 independent parasite, as has been supposed, and yet 

 its purpose in the animal economy is a mystery. 

 Mr. Gosse conjectures that its use may be, by holding 

 animalcules till they die and decay, to attract by 

 their putrescence crowds of other anunalcules, which 

 may thus be drawn within the influence of the 

 polype's ciliated tentacles. Fig. 7 h shows the form 



