128 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



4 females. 



3 



3 specimens. 



2 females. 



male, 

 female. 



male, 

 female. 



With Five Radial Canals, or Four and Five with Fork. 

 1 ; 2 ; 2 ; 2 ; ; 1 female. 



2 females and 1 male. 



1 



1 male. 



1 female. 



1 



1 



1 male. 



1 " 



1 female. 



1 



1 male. 



4 females and 1 male. 



1 ; 4 ; 4 ; 2 ; 3 females and 1 male. 



The variations in the shape of the genitals from a circular to an ellip- 

 tical outline to lobate, foliate, or elongate shape (Plate VIII. Fig. 21) is 

 usually connected with the growing together of the genitals of adjoin- 

 ing radial canals (Plate VIII. Fig. 18) or with their separation into two 

 distinct bodies when the radial canals fork (Plate III. Figs. 1, 5). 



It will be seen that in Eucope, as has been observed in Aurelia, the 

 tendency in the numerical variation of the genitals is greatest in the 

 direction of an increase rather than a diminution in their number. A 

 similar tendency is also noticed in the numerical variation of the radial 

 canals of the otoliths. 



