72 T. KOMAT: STUDIES ON TWO ABERRANT CTENOPHORES 



spread out to assume the state of the adult individual. 



(21). After the larval body has completed its metamorphosis, 

 there arrives a stage in which the main part of the canal-system consists 

 of eight pouches arranged around a central space much as in a certain 

 young stage of Gastrodes parasiticnm. 



(22). All the facts given above, both anatomical and embryologi- 

 cal, show clearly that, first, Coeloplana is nothing more than a highly 

 specialized ctenophore adapted to the creeping mode of life, and, second, 

 the flatness and dorsiventrality of the body of this animal has been 

 brought about not by the simple reduction of the main axis, but by 

 the out-spreading of the external half of the pharynx of the original 

 cydippid-like form. 



(22). The striking resemblance between Coeloplana and the Turbel- 

 laria is apparently no more than an instance of the phenomenon of 

 convergence and can not be looked upon as an evidence of a close 

 consanguinity of the former with the latter. 



