AND RELATED GENERA, SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 51 



like a sabre towards the oral disc, thick in the basal part but gradually narrowing 

 towards the tip, and of moderate length. Their arrangement is irregular, and recalls 



Fig. 1a. 



X 



<% x 



Fig. 1b. 

 Fig. 1. — Porponia antarctica ; A from the side, B from the disc. 



the condition in Halcurias (Endoccelactis). In the latter genus the true arrangement 

 is difficult to find, and this is even more the case in Porponia owing to the greatly 

 swollen bases of the tentacles. So far as I could find, the arrangement of the tentacles 



