Plate I. 



Fig. I. Ceratocepliale osaiuai in the atocons or immature phase, commonly 

 known under the name of " I tome." (Nat Size). 



Figs. 2-5. Immature specimens in different stages of transition into maturity 

 or the epitocous phase. A, males. B, females. (Nat. size). In 

 figs. 2A and 27?, it will be seen that the sexes differ slightly in 

 color of the body, which is now considerably stouter than in the 

 stage of growth represented in fig. 1. In figs. 3.1 and 37?, the 

 anterior portion of the body has undergone much more enlargement, 

 while the posterior portion remains nearly the same; the sexes are 

 easily distinguishable on account of their different colors. Figs. \A 

 and 47? represent worms somewhat advanced in the change into the 

 epitocous phase. Figs. 5A and 57? represent nearly full-grown 

 worms, in which the anterior portion of the body, that is the 

 epitoca about ready to swim out, is abruptly marked off from 

 the shrivelled and discolored posterior portion. Some posteriormost 

 segments have already been torn off and lost. 



Fig. 6. Epitocous phase, or the so-called " Bachi." Figs. 6A and 67? 

 represent respectively a male and a female epitoca of representative 

 dimensions. Fig. 6a and 6b represent a male and a female of 

 unusually small size. 



Fie;. 7. An epitocous female, showing the change of color into the greenish, 

 after swimming about for a while in exposure to light. (Nat. size). 



Fi<T. S. Dorsal view of that part of the body, in which the anterior epitocous 

 portion of the worm pas es over into the posterior portion which 

 is eventuallv shed off. 



