PLATE XIV. 



Fig. 



1. The anatomy of Tetrastemma Candida, chiefly with respect to the digestive and proboscidian 



systems. Considerably magnified. h°, abnormality of the right ganglion. 



2. Structure of the head of a young Tetrastemma melanocephala, showing the ganglia and the 



relation of the pigment-patch to the eyes. Considerably magnified. 



3. Digitate or lobate arrangement of the digestive canal of Nemertes gracilis. X 24 diam. 



4. Head and anterior portion of Nemertes carcinophila. f, powerful transverse fibres which 



retain the posterior part of the oesophagus in situ. X 180 diam. 



5. Superficial structure of the reservoir in Nemertes Neesii, showing the elaborate interlacing of 



the fibres. X 210 diam. 



6. Stylet from a marginal sac of Tetrastemma Candida (same animal as in fig. 6, Plate XIII). 



X 700 diam. 



7. Stylet from the central apparatus of the same specimen. X 700 diam. 



8. Stylet from a marginal sac of Tetrastemma melanocephala. X 700 diam. 



9. Stylet from the central apparatus of the same specimen. X 700 diam. 



10. Marginal stylet of Tetrastemma Robertianoe. a X 350 diameters, b X 700 diam. 



11. View of the under surface of the snout of Amphiporus pulcher. The mouth is indicated at w, 



the cephalic furrows and their branches at m", and the situation of the ganglia at i. 

 Enlarged under a lens. 



12. Transverse section of the wall of the oesophagus of A. lactifloreus, after mounting in chloride 



of calcium. X 210 diam. 



13. Compound cells from the wall of the digestive cavity of Tetrastemma dorsalis. X 350 



diam. 



14. Cephalic ganglia of Tetrastemma flavida. X 210 diam. 



15. Eye of Amphiporus pulcher from a dead and slightly injured specimen. X 210 diam. 



16. Portion of a sperm-sac from Tetrastemma flavida, exhibiting a streaky and granular aspect 



from the varying nature of the contents. X 350 diam. 



17. Granules from a developing sperm-sac of T dorsalis. X 400 diam. 



18. Spermatozoa of Amphiporus lactiflor ens. X 800 diam. 



