PLATE XXV 
Fig. 1—3. Acasta nitida n. sp. 
Fig. 1. a@ and J, scutum and tergum, internal view; magnified 10 diameters. 
c and d, scutum and tergum, external view; magnified 10 diameters. 
Fig. 2. Outer maxillae; magnified 44,5 diameters. 
Fig. 3. Fourth cirrus, pedicel and lower segments; magnified 100 diameters. 
Fig. 4—11. Acasta glans Lamarck. 
Fig. 4. Shell, young specimen, lateral view; magnified 4 diameters. 
Fig. 5. a@ and 4, scutum and tergum of full-grown specimen, internal view; magnified 4 diameters. 
Fig. 6. a@ and 6, scutum and tergum of young specimen, external view; magnified 4 diameters. 
Fig. 7. Labrum, with right-hand palpus; magnified 44,5 diameters. 
Fig. 8. Mandible; magnified 44,5 diameters. 
Fig. 9. Maxilla; magnified 44,5 diameters. 
Fig. 10. Outer maxillae; magnified 44,5 diameters. 
Fig. 11. Fourth cirrus, part of pedicel and lower segments; magnified 70 diameters. 
Fig. 12—16. Hexelasma arafurae n. gen. n. sp. 
Fig. 12. Shell, lateral view; magnified 3,25 diameters. 
Fig. 13. @ and 6, scutum and tergum, internal view; magnified 3,6 diameters. 
c and d, scutum and tergum, external view; magnified 5,2 diameters. 
Fig. 14. Labrum with palpi, central part; magnified 44,5 diameters. 
Fig. 15. a, right-hand-, 4, left-hand-mandible; magnified 44,5 diameters. 
Fig. 16. Maxilla; magnified 58 diameters. : 
