PLATE XL. 



SILURIAN SPECIES. 

 Fig. 



1 — 5. Strophomena euglypha, Sow. \,\ a,\ c. Exterior of both valves. 1 h. Longi- 

 tudinal section of both valves. 2. Literior of the ventral 

 valve. 3. Interior of the dorsal valve. All from the 

 Wenlock Limestone ; Dudley. 4. Exterior, and 5, in- 

 ternal cast, of the dorsal valve. Lovs^er Llandovery ; Sevin, 

 Llettyrhyddod, Llandovery. 



6 — 8. „ Walmstedti, Lindstrom. Wenlock Shale ; Pentland Hills. 6. Ex- 



terior of the dorsal valve. 6 a. Longitudinal section of 

 both valves. 6 b. Portion of shell-sculpture, enlarged. 

 In Mr. Henderson's Collection. 7. Internal cast of the 

 ventral valve. 8. Fragment of both valves, to show the 

 area. 



9 — 1 3. „ funiculata, M'Coy. Wenlock Limestone ; Dudley and Lincoln 



Hill. 9, 9 a. Exterior of the valves. 9 b. Section. 

 9 c. Shell-sculpture, enlarged. 10. Interior of the dorsal 

 valve. 10 a. The same, enlarged. 11. Interior of the 

 ventral valve. 12. Another specimen of the same valve. 

 13. Interior of ventral valve, enlarged. 



