A uew Species of Nectonemertes. 355 



Explanation of plates. 



The following abbreviations have been used in the explanation of the figures : 



hm basement membrane Iv lateral vessel 



by brain nt mouth 



coe intestinal coecum * vir median vessel 



civ cirrus 11 nerve 



(In dorsal nerve op opening of gonad 



go gonad pro proboscis 



int intestine sto stomach 



In lateral nerve 



Plate 21. 



Fig. 1. Kectonemertes pehgica n. sp., dorsal view. 3:1. 



Fig. 2. Anterior end, dorsal view, showing central nervous system, 

 proboscis, stomach and intestinal coecum with lateral pouches. 12 : 1. 



Fig. 3. Same, ventral view, showing gonads, nervous system and 

 alimentary canal. 12:1. 



Fig. 4. Blood and nervous systems of anterior end of body. 12:1. 



Fig. 5. Portion of middle section of body. The proboscis has been 

 removed and the dorsal portions of the intestinal pouches, present on left 

 side, have been cut away to expose their connections with ventral portions 

 of gut. 12:1. 



Fig. 6. Brain and principal nerves arising from it. Those shaded 

 are distributed to ventral side of body, do dorsal brain commissure, j)rn 

 proboscis nerves. 



Fig. 7. Section through anterior end of rhynchocoel. be buccal 

 cavity, bv blood vessel, bn longitudinal muscles, up nerve plexus. 

 Fig. 8. Gonads, with muscular walls and outlet to exterior. 

 Fig. 9. Posterior end of body, dorsal view. 12 : 1. 

 Zool. Jahrb. XXllI. Abt. f. Anat. 23 



