PLATE VIII. 



Carboniferous Trilobites. 

 Figs. 1 — 8. — Brachymetopus ouralicus, De Verneuil, sp., 1845. (P. 48.) 



Fig. 1. — Head-shield, having both eyes perfect ; enlarged four times natural size ; from the 

 Carboniferous Limestone, Settle, Yorkshire. 



Original specimen in the Woodwardian Museum, Cambridge. 



Fig. 2. — Another specimen, right eye wanting ; neck-lobe well seen ; enlarged four times natural 

 size ; from same locality and formation as preceding. 



Original in the British Museum (Natural History) Cromwell Road. 



Fig. 3. — A somewhat larger head-shield, enlarged three times natural size, having one of the 

 cheek-spines perfect, but wanting the eyes ; from the same locality and collection as Fig. 1. 



Figs. 4 and 5. — Two specimens, both with their head-shield and pygidium preserved close 

 together, each in its own piece of matrix ; enlarged twice the natural size ; from the same locality, 

 formation, and collection as figs. 1 and 3. 



Fig. 6. — A very large pygidium, nearly perfect ; magnified twice the natural size ; from the same 

 locality and collection as figs. 1, 2, 4, and 5. 



Fig. 8. — Another pygidium, enlarged twice natural size ; from the Carboniferous Limestone near 

 Cork. 



The original specimen in the collection of Joseph Wright, Esq., F.Q-.S., of Belfast. 



Fig. 7. — Outline figure of Brachymetopus ouralicus restored and enlarged. 



Figs. 9 — 13. — Braciiyhetopus Maccoyi, Portlock, sp. (P. 52.) 



Fig. 9. — A pygidium, enlarged three times, from the Black Carboniferous Limestone, Monaster. 



The original specimen in the collection of Joseph Wright, Esq., F.G-.S., of Belfast. 



Fig. 10. — Head-shield of same from the same locality and collection as the above ; enlarged three 

 times. 



Fig. 11.- — Another head-shield of same, showing anterior margin of head well preserved, enlarged 

 three times; from the Lower Limestone Shale (Carboniferous Limestone), County Limerick. 



Original specimen in the Museum of the Geological Survey of Ireland, Dublin. 



Fig. 12. — Head-shield having both cheek-spines preserved ; enlarged three times natural size ; from 

 the same locality and collection as figs. 9 and 10. 



Fig. 13. — Outline figure. Restored and enlarged of B. Maccoyi. 



Fig. 14. — Pygidium, probably of Griffithides seminiferus (see PI. V), from the Carboniferous 

 Limestone, Settle, Yorkshire. (P. 28.) 



Original specimen in the Woodwardian Museum, enlarged twice the natural size. 



Fig. 15. — Brachymetopus discors, M'Coy. Pygidium, magnified six times, from the Carboniferous 

 Limestone, Little Island, Cork. (P. 54.) 



Original specimen from the collection of Joseph Wright, Esq., F.G.S., Belfast. 



Fig. 16. — Brachymetopus hibernicus, H. Woodw., sp. Pygidium enlarged twice the natural size. 

 From the Carboniferous Limestone, Kildare, Ireland. (P. 55.) 



The original specimen in the British Museum (Natural History), Cromwell Road. 



