70 University of California Publications in Zoology. [Vol.8 



and top of shaft parallel. Point in^rted into shaft about one-fifth its own 

 height. Pulp-canal slightly swollen just below point, and located somewhat 

 nearer back of jaw. Pulp evenly distributed. 



But two specimens were well enough preserved to permit 

 accurate measurements. They are given below, following which 

 the measurements of S. arctica are given. 



1 All measurements made in per cent of total length of animal. 



- Per cent of posterior fin in front of tail-septum. 



Anterior teeth in S. arctica 7-8, posterior teeth lS-14, seizing jaws 10-11. 



This table presents a great similarity between the two species. 

 The only noticeable difference is that, as a rule, the interval from 

 anterior tin to ventral ganglion is larger in S. arctica. However, 

 in nos. 7, 8, and 9 we see transition cases. 



The other differences between S. elegans and S. arctica are as 

 follows : 



1. The body of the former is flabby, while that of S. 

 arctica is firm. 



