PLATE T. 



Fig. 1. Sternas2ns princeps, u. sp. 

 Three times the natural size ; viewed from the ventral aspect. 



Fig. 2. Echiurus unicinctus, von Drasche ; f . 



A. Anal vesicles (with ciliated funnels). 

 a Anal opening. 



B. Set£e. 



h. The posterior circle of setse. 



/3. Fixing muscles of the intestine. 



D. Intestinal canal. 



a. Diverticulum of the intestine. 



g. Blood-vessel accompanying intestine. 



K Cloaca. 



L. Body-wall. 



n. Ventral nerve-cord. 



E. Proboscis. 



Rm. Circular muscles of the body-wall. 



S. Pharynx. 



2. vSegmental organs. 



sp. Spiral tubes of the segmental organs. 



Fig. 3. BoneUia suhmii, n. sp. ; natural size. 



The figure is copied from tlie original drawing of Dr. v. WiUemoes-Suhm. Both the 

 hind end of the body and the proboscis were torn away. 



0. Mouth opening. | v. Opening of uterus. 



