Tentacles 



Tentacles 



Lophophore 



Buds 



Fig. 18.2. Phylum Hemichordata. A, general features of Rhabdo- 

 pleura; B, Cephalodiscus dodecalophus, ventral view. C, reconstruction 

 of what is interpreted as a floating community of colonies of the 

 Ordovician graptolite Diplograplus, viewed from above. {A and B, 

 redrawn from C. DawydofT in P.-P. Grasse, Ed., Traile de zoologie, 

 1948, vol. 11, A after Delage and Herouard, B after Mcintosh; C, 

 redrawn, after Ruedemann, from Y. Delage and E. Herouard, 

 Traile de zoologie concrete, 1901, vol. 2.) 



544 



