PLATE XVIII 



Fig. i. Ba/anus tennis Hoek. 



Fig. I. Outer maxillae ; magnified 64 diameters. 



Fig. 2 — 12. Balanus socialis Hoek. 



Fig. 2. Two specimens attached to a piece of shell ; magnified 10 diameters. 

 Fig. 3. a and b, scutum and tergum, internal view; magnified 10 diameters. 



c and d, scutum and tergum, external view; magnified 10 diameters. 

 Fig. 4. a and b, two sections through the walls: a, near the orifice and b, near the basis; 

 magnified 15 diameters. 



Labrum, with right-hand palpus; magnified 64 diameters. 



Mandible ; magnified 64 diameters. 



Maxilla; magnified 64 diameters. 



Edge of maxilla with spines; magnified 206,5 diameters. 

 Fig. 8. Outer maxillae ; magnified 64 diameters. 



Fig. 9. Sixth cirrus, two of the middle segments; magnified 64 diameters. 

 Fig. 10. Specimen with swollen compartments and elongated carina; magnified 10 diameters. 

 Fig. 11. Specimen with very broad alae ; magnified 10 diameters. 



Fig. 12. Tergum of the specimen with very broad alae: a, internal, b, external view; magnified 

 10 diameters. 



Fig. 13 — 19. Balanus maldivensis Borradaile. 



Fig. 13. Specimen attached to the spine of an Echinid; magnified 10 diameters. 

 Fig. 14. a and b, scutum and tergum, internal view; magnified 10 diameters. 

 c and d, scutum and tergum, external view; magnified 10 diameters. 

 Fig. 15. Labrum, with left-hand palpus; magnified 144 diameters. 

 Fig. 16. Mandible; magnified 144 diameters. 

 Fig. 17. Maxilla; magnified 144 diameters. 

 Fig. 18. Outer maxillae; magnified 64 diameters. 

 Fig. 19. Sixth cirrus, last segment but 7 th ; magnified 64 diameters. 



Fig. 20 — 22. Balanus auricoma n. sp. 



Fig. 20. Group of specimens attached to a stone ; magnified 10 diameters. 

 Fig. 21. Horizontal section through the valve near the basis; magnified 14 diameters. 

 Fig. 22. a and b, scutum and tergum, internal view; magnified 8,2 diameters. 

 c and d, scutum and tergum, external view; magnified 8,2 diameters. 



