476 



The nervous system was described as follows : 



*' Attached to the external surface of the oesophagus, on its 

 rectal aspect, may be seen just below the mouth, an oval body 

 of a yellowish colour, with a cavity or ventricle in its interior. 

 That this is a nervous ganglion there can be no doubt, and 

 I have succeeded in distinctly tracing nervous filaments in 

 connexion with it. From each side may be seen passing oflF 

 a rather thick cord which takes a course backwards, and im- 

 mediately enters the tubular arms of the lophophore. It 

 now runs along the roof of the tube, giving off at regular in- 

 tervals a filament to each tentacle upon the outer margin of 

 the arm. When it arrives at the extremity of the arm it turns 

 on itself, and in its retrograde course gives off similar fila- 

 ments to the tentacles placed upon the inner margin. It finally 

 terminates by uniting with its fellow at the bottom of the sinus 

 of the crescent. Just before entering thearms, filaments are sent 

 forwards to the tentacles, placed upon the anterior margin of 

 the lophophore. From the upper edge of the ganglion some 

 filaments would seem to pass off to the mouth and its valvular 

 appendage, and from each side a filament passes forwards to 

 embrace the oesophagus ; but I could not succeed in tracing a 

 perfect collar round this tube. Round the margin of the 

 lophophore at each point, corresponding to an interval be- 

 tween two tentacula, may be observed a minute brilliant spot, 

 an appearance which, perhaps, we may truly interpret as a 

 special organ of sense. This opinion, however, is one which 

 I throw out with much diffidence, and one which will require 

 further corroboration before it can be viewed as established." 



The author gave the following description of the free loco- 

 motive embryos of Alcyonella : 



" While engaged in the examination of a specimen of Al- 

 cyonella fungosa, in the month of October last, I liberated 

 from the mass an active locomotive animalcule, possessing 

 certain points of resemblance with the adult Bryozoon, of 

 which it was evidently one of the early phases of development. 

 It consisted of a common sac enclosing two imperfectly de- 



