Explanation of the Plates. 



Plate I. 



Fig. 1. Dinonemertes investigatoris. Fullgrown specimen, dorsal 

 view. s /e natural size. 



2. As fig. 1, but lateral view. 5 k natural size. 



3. Dinonemertes investigatoris. Young specimen, ventral 

 view. 5 6 natural size. 



4. Pendonemertes Levinseni. Ventral view. X 2. 



5. Bathynemertes Hubrechti. Dorsal view. X 1-5. 



6. Burgeriella notabilis. Dorsal view. X 1-2. 



7. Forepart of the same specimen as fig. 6, but ventral view 

 after clarification in cedar oil. For the sake of convenience, 

 the first pair of diverticula on the intestinal cascum have 

 not been included in the figure. X 7. 



„ 8. Crassonemertes robusta. X 3. 



„ 9. Plotonemertes adhcerens. Lateral view. X 2.5. 



10. Caudal region of the specimen shown in Fig. 9; ventral 



view, showing the double glandular organ of the surface 



above. X abt. 10. 



Plate II. 



Fig. 11. 

 „ 12—13. 



„ 14-15. 



„ 16—22. 



24- 



23. 

 -25. 



26. 



Ventral view. X a bt. 7. 

 Ventral and lateral view. 



Nectonemertes primitiva ?. 

 Nectonemertes primitiva a*. 

 X abt. 7. 



Nectonemertes mirabilis d* (14) and ¥ (15). Ventral 

 view. X 2.4. 



Series of males of N. mirabilis, showing growth of 

 tentacles. X 3.5. 



Nectonemertes minima. Ventral view. X 8.5. 

 Phallonemertes Murrayi, a* (24) and ¥ (25) both ven- 

 tral view. Penes distinctly visible on lower side of head 

 of male. X 2.4. 

 Natonemertes acutocaudata. X 7. 



