PLATE III. 



Fio. Page. 



1. Hyhodus ensis, sp. nov. (?) ; dorsal fin-spine. — Middle Purbeck Beds; 



Swanage, Dorset. B. M. no. 46908. 11. 



2. Ditto; imperfect large dorsal fin-spine. — Ibid. Dorset County Museum. 11. 



3. Ditto; small dorsal fin-spine. — Ibid. B. M. no. 33476. 11. 



4. 5. Hi/bodiis atrlctiii^, Agassiz ; two dorsal fin-spines, the first exhibiting 



growth-lines.— Ibid. B. M. nos. 28447, P. 2835. 13. 



6. LLijbodus h(i>;a)iiis, Egerton(?); dorsal fin-spine. — Wadhurst Clay; Eccles- 



bourne, near Hastings. Rufford Collection (B, M no. P. 8938). 10. 



7. Ditto; dorsal fin-spine. — Wealden ; Hastings. RufTord Collection (B. M. 



no. P. 6936). 10. 



8. Uijhodus striatnlits, Agassiz ;, part of distal half of spine. — Tunbridge 



Wells Sands ; Tilgate Forest. Mantell Collection (B. M. no. 2686). 13. 



All tlie figures are of the natural size. The outlines 1 a-8 a represent transverse 

 sections of the spines at the points marked by cross-lines. 



