216 DE. W. G. EIDEWOOD ON THE CRANIAL OSTEOLOGY OF 



EXPLANATION OF THE PLATES. 

 Plate 22. 



Pig. 1. Mormyro'ps ddiciosus. 

 2. 

 3. 



Eight side of skull (slightly enlarged). 

 Cranium, dorsal view (slightly enlarged). 

 Cranium, left side (slightly enlarged). 

 Hyopalatine arch of left side, with opercular 



bones and mandible, mesial aspect (slightly 



enlarged). 



Plate 23. 



Fig. 5. Fetroceplialus haiie 

 6. 

 7. 



9. 



Eight side of skull ( x 2). 



Cranium, dorsal view (x2). 



Cranium, left side (x2). 



Cranium, back view ( X 2). 



Hyopalatine arch of left side, with opercular 



bones and mandible, mesial aspect (X2). 

 Eight maxilla (x2). a, horizontal, posteriorly 

 directed process ; b, process lying immediately 

 over the posterior part of the premaxilla ; 

 c, antero-ventral edge, namely, that along 

 which teeth might be expected to occur. 

 IL Gymnarchus niloticus. Eight ramus of mandible, mesial aspect 

 (XI). 



10. Mormyrus caschive. 



Fig. 12. Notopterus kapirat. 

 13. 

 14. 

 15. 

 16. 



17. 



Plate 24. 



Eight side of skull (nat. size). 

 Cranium, dorsal view (slightly enlarged). 

 Cranium, left side (slightly enlarged). 

 Cranium, back view (slightly enlarged). 

 Hyopalatine arch of left side, with mandible, 



mesial aspect (nat. size). 

 Hyobranchial skeleton, dorsal view. The epi- 



branchials and phai-yngobranchials of the right 



side are not shown (nat. size). 



Plate 25. 



Fig. 18. Hyodon alosoides. Eight side of skull (nat. size). 



19. „ „ Cranium, dorsal view (slightly enlarged). 



20. „ ,, Cranium, left side (slightly enlarged). 



21. „ ,, Cranium, back view (slightly enlarged). 



22. „ „ Hyopalatine arch of left side, with opercular bones 



and mandible, mesial aspect (nat. size). 



