PLATE XLIX. 



SILURIAN SPECIES. 



Fig. 

 1 — 12. Leptcena C.) la:viyata,^QW. 1,2. The original specimen. 2 a. Enlarged. Wenlock ; Burring- 



ton, Salop. Mus. Geol. Soc. 3, 4. From near Dudley. Gray's Coll. 

 in the Brit. Mus. 4, 5. Show the small apicial foramen. G. L. 

 lecvissima, M'Coy, ' Sil. Foss. Ireland,' pi. iii, figs. 7, 8, 12. 

 Leptcena lepisma, var. minor, Phillips and Salter (not of Sow.), after 

 figures in the 'Mem. Geol. Survey,' vol. ii,pl. xxvi, figs. 3, 4. Upper 

 Silurian ; Builth. 



13, 14. Chonetes lepisma, Sow. 13. Aymestry Limestone; Malvern. Mus. Pract. Geol. 13a. En- 

 larged. 14. The original specimen of Leptcena lepisma. Sow., 'Sil. 

 Syst.,' pi. viii, fig. 7. 14 a. Enlarged. Lower Ludlow ; Garden 

 House Quarry, Aymestry. Mus. Geol. Soc. 



15 — 19. „ 1 minima. Sow. 15. The original example of " Leptcena minima," Sow., 'Sil. Syst.,' 



pi. xiii, fig. 4. Wenlock Shale; Burrington. Mus. Geol. Soc. low. 

 Enlarged. 16, 17. Var. Grai/i,T)av. 16a, i. Enlarged. 17. Interior 

 of dorsal valve. Wenlock Shale; Dudley. 18. Lower Ludlow; 

 Vinnal Hill, Ludlow. Mus. Pract. Geol. 19. Lower Ludlow; Elton 

 Lane, Ludlow. Dr. Holl's Collection. 



20 — 22. Leptcena (vel Chonetes ?) temdssime-striata, M'Coy. 20. After the original figure in ' Sil. Foss. 



Irel.' Caradoc (?) ; Slieve Roe, Rathdrum, County Wicklow. 21. 

 Another crushed example. Same locality. 22. Specimen figured by 

 M'Coy, 'Brit. Pal. Foss.,' pi. i H, fig. 44, from Llandeilo. (This is 

 an undetermined species.) 



23 — 26. Chonetes striatella, Dalman, sp. 23. After Sowerby's original example of "2,. lata," 'Sil. 



Syst.,' pi. XX, fig. 8. Upper Ludlow ; Ludlow. 24. Ludlow. 25. 

 Wenlock Shale ; Pentland Hills. 26. Interior of the dorsal valve, 

 enlarged. Dudley. 



27 — 29. O^-^Amna a«/sce>irfe«« (?), Pander, sp. 27. Lower Llandovery ; Cefncoedog, Corwen. From an im- 

 pression taken in gutta-percha from a cast in the Woodwardian 

 Museum at Cambridge. 28. Internal cast of a ventral valve. 29. 

 From Cefn Coch. ? Collections of Messrs Parrott and Davies. 



30. Liuffula petalon. Ricks. Arenig Rocks ; Whitesand Bay. 



31. Lingvlella lepis, Salter. Internal cast. Lower Tremadoc ; Penmorfa Church, Portmadoc. 31 a. 



Enlarged. 

 32 — 35. ,, ferruginea, ^s[ter. 32. Nat. size ; after Mr. Salter's figures. Msenevian, St. David's. 



33. Another example ; and 33 a, enlarged. 34, 34 a. From the purple 

 beds of the Harlech group, St. David's. Copied from the original 

 figure of var. ovalis, Salter. 35, 35 a. Porthclais Harbour, St. David's ; 

 from the lowest beds of the purple Cambrian rocks. The earliest 

 Brachiopod hitherto discovered. 

 36 — 40. Acrotretn I Nicholsoni, Dav. Upper Llandeilo ; Dobb's Linn, Maffat. The smaller figures are 



of the natural size. 

 41, 42. Discina pileohis, Ricks. Msenevian rocks; Porth-y-rhaw Valley, St. David's. 41a, 42 a. En- 

 larged. 

 '13, 44. „ • {Trematis) corona, Salter, CBradoc, Bala Shales ; Dufton-Pusgill, Westmoreland. 



Woodwardian Museum, Cambridge. 



