48 Invertebrate Zoology. 



"bird's-head " structures, or avicularia, will be found. 1 Near 

 the proximal ends of certain older zooecia, on the upper 

 surface, spherical bodies will be found. They are egg-cap- 

 sules, or ocecidy and have a diameter about equal to that of 

 the zooecia. 



By focussing deeply into the distal portion of one of the 

 zocecia, an irregular oval opening will be observed to lead 

 from its inner side. This opening is the rosette or commu- 

 nication plate and leads into the proximal end of the zoce- 

 cium next above and on the opposite side of the double 

 row. 



In an alcoholic specimen thaWhas been properly killed 

 and preserved, the walls of each zocecium will be found to 

 extend distally and to be terminated by a circle of fourteen 

 long tentacles, the zooecium together with the fleshy parts 

 being known as &polypide. The knob-shaped body bearing 

 the tentacles is the lophophore. It is pierced by the mouth 

 opening, which is placed in the centre of the tentacular 

 crown. In life, the cilia covering the tentacles whip the 

 food into the mouth, the pharyngeal cilia there carrying it 

 still further into the digestive tube. The anal opening is to 

 be found on the inner side of the lophophore just below the 

 circle of tentacles. It is often more readily found if the 

 zooecium be examined from the lower side. Make a drawing 

 of a polypide. 



Digestive System. The digestive tract is V-shaped. 



The pharynx leads into a stomach, which is provided with a 



i 



1 The jaws of the avicularia, during life, are frequently closed upon 

 small animals, the decaying bodies of which may attract smaller 

 organisms upon which the Bugula feeds. 



