Text-figure 3.— Cephalodiscus liodnsoni. Figures illus- 

 trating the development of the plumes of the buds ; series continued 

 from text-fig. 2. M shows the left side of a bud in which the fifth 

 pair of plumes are swollen knobs ; the other figures are dorsal views 

 of the collar and appendages (plumes and post-oral lamella) of older 

 buds, represented in whole (N and R) or in part only (0, P, Q, and 

 S). The fifth pair of plumes have the form of clavate knobs in N, 

 and the sixth in R. All figures enlarged 62 diameters. For ex- 

 planation of the lettering see end of paper. 



