SECT. VIII 



POLYZOA 



183 



vascular system, and the central part of the nervous system consists 

 of a single ganglion (Fig. 96, gang.}, placed between mouth and anus. 

 The sexes are united, and there is a free-swimming ciliated larva. 



Probably allied to the ordinary Polyzoa thus briefly characterised, and 

 usually assigned to that class, are a small number of genera, of which 

 the best known are Pedicellina (Fig. 97), Urnatella and Loxosoma, 



