TAB. XVIII. 



Fig. 



1. Dithyrocaris Permiana (X 50). 



a. Left valve. 



b. Profile. 



c. Anterior aspect of two valves closed — from a worn cast. 



d. Cast of a carapace, the upper valve removed, the lower remaining, 



but worn at one extremity. 



2. Cythere Morrisiana ( X 25). 



a. Perfect carapace, right valve upwards. 

 h. Dorsal aspect, 

 c. Anterior aspect. 



3. Bairdia curta (X 30). 



a. Perfect carapace, left valve upwards. 



b. Dorsal aspect. 



c. Anterior aspect. 



4. Cythere Geinitziana (X 25). 



a. Perfect carapace, right valve upwards. 



b. Dorsal aspect. 



c. Anterior aspect. 



5. Cythere elongata ( X 50). Perfect carapace. 



6. Cythere Kutorgiana (X 50). Cast of carapace, the left valve removed, 



the other remaining, its edge visible. 



7. Bairdia gracilis (X 50). Worn cast of carapace. 



8. Cythere biplicata (X oO). Cast of carapace, one valve removed, the 



edge of the other visible. 



9. Cythere inornata ( X 50). Perfect carapace, left valve upwards. 



10. Cythere acuta (X 50). Perfect carapace, left valve upwards. 



11. Cythere nuciformis (X 50). 



a. Perfect carapace. 



b. Dorsal aspect. 



c. Anterior aspect. 



12. Dithyrocaris giypta ( X 40). Left valve. 



13. Serpula (?) pusilla (X 25). 



a. Perfect. 



b. Perfect. 



c. Central coil. 



d. Transversely fractured, showing the broken ends of the outer 



coils, 1, 2, 3, 4, 5. 



