Text-figure G. — Cephalodiscus nigrcsceiis. Figures illus- 

 tratine; the development of the i)lumcs of the buds. A, B, C, 1) 

 and ¥ arc dorsnl views of complete buds; E shows the plumes dis- 

 sected from a bud a little earlier than F. The first pair of plumes are 

 just appearing in E, the second in C, the third in D, and the fourth 

 in F. The series is continued in text-fig. 7. AH figures enlarged 

 G2 diameters. For explanation of the lettering see end of paper. 



