ON DINOPHILUS GIGAS. 269 



dicated is exactly furnished by the Rhabdocoel pharynx 

 (fig. 16). 



We seem, therefore, to have in Dinophilus a form which, 

 related on the one hand to the Archiannelids, retains on the 

 other many features characteristic of the ancestor common to 

 those groups (especially Chaetopods, Gephyreans, Mollusca, 

 Rotifers, and Crustacea) which possess a more or less modified 

 trochosphere larva ; and of these the relations of the body cavity, 

 of the excretory system, and of the pharynx, seem to point 

 unmistakeably to a Turbellarian oi'igin. 



