﻿BRITISH FOSSIL CEPHALOPODA. 



Plate IX. 



Fig. 



1. Orthoceras politum. — From the Bala Series, Glenwhapple. In the Wood- 



wardian Museum. Perhaps M'Coy's type. 



2. Ibid. — From the same locality and collection, a, diagram showing the position 



of the siphuncle at the small end ; b, showing its position at the large end. 



3. Orthoceras Bacchus. — From the Lower Ludlow, Ledbury. In the collection 



of Dr. Grindrod. 



4. Ibid. — From the Wenlock Shale, Usk Tunnel. In the Museum of Practical 



Geology. 



5. Ibid. — From the Lower Ludlow, Ledbury. In the collection of Dr. Grindrod. 



Showing finer ornaments when young. 



6. Ibid. — Diagram to show the form of the elements of the siphuncle. From a 



specimen in the same collection. 



7. Ibid. — From the Lower Ludlow, Dudley. In the Woodwardian Museum. A 



very ornamented fragment, showing transverse folds. 



8. Orthoceras politum. — From the Bala Series, Glenwhapple. In the Museum 



of Practical Geology. Showing the unsymmetrical siphuncle. 



9. Orthoceras Grindrodi. — From the Lower Ludlow, Ledbury. In the collection 



of Dr. Grindrod. 



