94 A. OKA. 



braucliiijo- of the cœuœciuni iu Vaci. iie]atirio.s;i is .shown in lii"-. 3. 

 PJ. XVII.. It is (lichotomouä with a sh(;/rt branch at each axiL 

 The branches are no bent that all the poJypides stand npright and 

 as the phnnous tentacles cover the whole surface of the coh)ny, their 

 regular symmetrical arrangement cannot be discerned without chjse 

 examination. 



The general plan of the structure of a [xdypide and its relation 

 to ihe cystid are shown in tig. 4, I'l. XVII. The alimentary canal 

 is bent in the sliape of the letter V, and hangs freely in the perigastiic 

 cavity. The mouth guarded by a tongue-like epistome (Epist.) is 

 surrounded by a number of tentacles (Tent.) arranged along the 

 entire margin of a horse-shoe shaped Jophophore (Loj)Jt.). The anus 

 opens outside the tentacular area near the mouth, on that side of the 

 body on which the arms of the lophophore stretch out. A nervous 

 ganglion (X. Gang.) is seen on the anal side (jf the oesophagus. A 

 thin hollow tube, called funiculus, in which the statoblasts are 

 developed, joins the angle of the alimentary canal with the cystidal 

 wall. An ovarv (Orr.) is seen inside the tip of the cœnœcial branch. 

 The length of a polypide from the tip of the tentacles of the angle 

 of flexure of the alimentary canal is about 4 mm. 



Although the term " individual " as applied to such foi'uis as 

 polyzoa is very diihcult to detine, yet homulogously with its nearest 

 relative, the Ijrachiopods, each polyzooid might be regarded as an 

 individual in the (ordinary sense of the word. Polyzoan individuals 

 show a close analog}' to " phytons " of plants. 



The polypide and the cystid that constitute a pol\zoüid, are 

 respectively vegetative and reproductive in function. As will be 

 seen further on, all the functions for the preservation of the species 

 are performed by the latter, the funiculus being regarded as a part of 

 it, while the former serves to procure nourishment to the cystid. 



