I90I W. A. BAILY— RHYNCHELMIS 317 



PLATE XVII. 



RHYNCHELMIS 



Fig. I (Tafel xxi, fig. i.) — Dorsal view of the anterior 

 portion of a young worm : g Cerebral ganglion ; vv Dor.sal 

 vessel ; a Loops of the lateral vessel. 



Fig. 2 (Tafel xxi, fig. 2.) — The same from the ventral 

 side, vv Branches of the ventral vessel; n Degenerating 

 nephridia of the anterior segments. 



Fig. 3 (Tafel xxi, fig. 3.) — Older stage of the young 

 worm, vd Dorsal vessel ; a Anterior ; b Posterior lateral 

 vessels of a segment ; g Cerebral ganglion. 



Fig. 4 (Tafel xxviii, fig. 8.) — Longitudinal section through 

 two body-segments of the adult Rhynckelmis, which has 

 developed a portion of the intestinal wall with the vascular 

 network (dg), the ventral vessel (vv), and the ventral cord 

 (gz) ; d Division of segments ; 7nv Median vessel between 

 the intestinal network and the ventral vessel ; a Preseptal 

 side vessels ; Jtch Neuro-chord ; /;;/ Long muscle of the 

 ventral chord ; m Ring-muscle of the ventral cord. 



