PLATE XXV 



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



Fig. i — 3. Acasta nitida n. sp. 

 Fig. 



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. 



a and b, scutum and tergum of full-grown specimen, internal view; magnified 4 diameters. 



a and b, scutum and tergum of young specimen, external view; magnified 4 diameters. 



Labrum, with right-hand palpus ; magnified 44,5 diameters. 



Mandible; magnified 44,5 diameters. 



Maxilla; magnified 44,5 diameters. 



Outer maxillae; magnified 44,5 diameters. 



Fourth cirrus, part of pedicel and lower segments; magnified 70 diameters. 



Fig 

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 Fig 

 Fig 

 Fig 

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5 

 6 



7 



8 



9 

 10 

 1 1 



Fig. 12 — 16. Hexelasma arafurae n. gen. n. sp. 



Fig. 12. Shell, lateral view; magnified 3,25 diameters. 



Fig. 13. a and b, 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-, b, left-hand-mandible ; magnified 44,5 diameters. 

 Fig. 16. Maxilla; magnified 58 diameters. 



