PLATE XLVII 



SILURIAN SPECIES. 



Fig. 

 1 — 4. Strophomena Siluriana, Dav. Lower Silurian; Fairy Gill, Cautley, near 



Sedberg, Yorkshire. 1 a, 2 a, 2 b. Enlarged. 

 5, G. ,, Fletcheri, Dav. Wenlock Shale ; Benthal Edge. 5 a. Enlarged. 



7 — 18. Leptmna tenuicincta, M'Coy. 8 — 15. Various modifications in shape and 



stages of growth. Caradoc ; Lledfron, Llanfyllin, 

 Girvan, Tyrone, and the Chair of Kildare. 16, 17. 

 Interior of the dorsal valve, enlarged. 16. From 

 Sholes Hook, Haverfordwest. 17. From Tyrone, 

 Ireland. 17 «. Internal cast of the dorsal, and 18, 

 internal cast of the ventral valve, enlarged. Lower 

 Llandovery; Rhosfawr, near Llanfyllin. Several of the 

 specimens are in the Mus. Pract. Geol. 



19, 20. „ transversalist var. Youngiana, Dav. Caradoc; Craighead Quarry, 



Girvan, Ayrshire. 19 c, </. Enlarged. 



21 — 25. ,, 5cm«, Salter. 21. Upper Llandovery; Norbury, Bishop's Castle. 



22. Interior of the dorsal valve, and 23, of the ven- 

 tral valve. Lower Llandovery ; Gas-works, Haver- 

 fordwest. 22 a, 23 a. Enlarged. 24. Interior of 

 the ventral, and 25, of the dorsal valve. Caradoc ; 

 Sholes Hook, Haverfordwest. 24 a, 25 a. Enlarged. 

 Mus. Pract. Geol. 



