PLATE 1. 
Figs. 1, 2. Limacina triacantha (Fischer). 
Fig. 1. Shell, from the aperture ; magnified fourteen diameters. 
Fig. 2. Shell, from the apex ; magnified fourteen diameters. 
Figs. 3, 4. Limacina antarctica, Woodward. (After Hooker’s unpublished figures.) 
Fig. 3. Shell, from the aperture ; magnified ten diameters. 
Fig. 4. Shell, from the apex ; magnified five diameters. 
Fig. 5. Limacina helicoides, Jeffreys. Shell, from the aperture ; magnified eight 
diameters. 
Fig. 6. Limacina australis (Eydoux and Souleyet). Shell, from the aperture ; magni- 
fied eight diameters. 
Figs. 7, 8. Peraclis reticulata (d’Orbigny). 
Fig. 7. Shell (from deep-sea deposit), from the aperture ; magnified twelve diameters. 
Fig. 8. Operculum, from the outside, a, Surface of insertion. 
Figs. 9, 10. Peraclis bispinosa, n. sp. 
Fig. 9. Shell, from aperture ; magnified six diameters. 
Fig. 10. Shell, from apex; magnified seven diameters. 
Figs. 11-14. “ Agadina” stimpsoni, A. Adams. 
Fig. 11. Shell, from aperture, with operculum in situ ; magnified eighteen diameters. 
Fig. 12. Shell, from apex; magnified twenty-two diameters. 
Fig. 13. Animal, from left side; magnified twenty diameters, a, velum; b, visceral 
mass ; c, aperture of pallial cavity ; d, operculum ; e, foot.. 
Fig. 14. Lower surface of the foot ; magnified twenty diameters, a, operculum. 
Figs. 15, 16. “ Agadina ” sp. 
Fig. 15. Shell, from aperture; magnified twenty-two diameters. 
Fig. 16. Shell, from umbilicus; magnified twenty-two diameters. 
