6o DISCOVERY REPORTS 



Table XX by the letters A or B, these letters corresponding respectively to the forms 

 with narrow and broadened proximal portions. As in the description already given, 

 the form with narrow-based spine is restricted to larvae of smaller size, whereas the 

 broadened form is found in the larger seven-spined larvae. As all later larvae have the 

 broadened form of innermost postero-lateral, the letter J5 has been omitted in descrip- 

 tions of them. 



Table XXI. Length frequency of larvae from St. 374 arranged according to 

 the number of terminal telson spines 



Antenna. The development of the antenna from its primitive form as a swimming 

 appendage into a specialized scale and flagellum takes place within the range of larvae 

 found at this station. The way in which this is brought about is shown in Fig. 13. 



The change of the outer ramus into a flattened scale follows the normal course de- 

 scribed in other euphausians. 



