﻿BRITISH FOSSIL CEPHALOPODA. 



Plate III. 



Fig. ?^ e 



1. Orthoceras mendax. — Salter's type specimen. From the Durness Limestone. -- 81 



In the Museum of Practical Geology. 



2. Orthoceras baculolde. — From the Durness Limestone. In the Museum of--^ 2 - 



Practical Geology. 



3. Orthoceras durinum. — From the Durness Limestone. In the Museum of -- 8 3 



Practical Geology, a, part of another specimen showing the double lines on 

 the siphuncular area. 



4. Orthoceras peranstulatum. — From the Bala Series, Desertcreat. In the--8Y 



Museum of Practical Geology. One of Portlock's types. 



5. Orthoceras gracile. — From the Bala Beds, Ardwell. In the Museum of- -85" 



Practical Geology, a, details of the ornaments magnified. 



6. Orthoceras mendax. — From the Durness Limestone. In the Museum of~~ 81 



Practical Geology. One of the specimens figured by Salter as 0. vertebrate. 



7. Orthoceras Nicholianum. — From the Lower Ludlow rocks, Ledbury. In— B$ 



the collection of Dr. Grindrod. a, two ribs magnified to show the orna- 

 ments. 



8. Ibid. — From the same locality and collection, possibly the actual continuation of -~8B 



the original of fig. 7. 



9. Orthoceras gracile. — From the Bala Shales, Desertcreat. In the Museum --$5- 



of Practical Geology. The specimen figured by Portlock as 0. tubicinella. 

 a, b, c, details of ornament in various specimens. 



10. Orthoceras adornatum. — From the Ludlow Passage Beds, Kington. In the— J 01 



Museum of Practical Geology. 



11. Orthoceras perthstens. — From the Durness Limestone. In the Museum of--/3^ 



Practical Geology. 



12. Orthoceras velatum. — From the Bala Shales, Cynwyd. In my collection. —87 



a, the surface magnified. 



13. Orthoceras kendalense. — From the Upper Ludlow, Kendal. In the Museum --700 



of Practical Geology, a, septal surface, showing vascular markings. 



14. Orthoceras arcuoliratum. — From the Bala Limestone, Wrae, Broughton. In --§3,$^ 



the Woodwardian Museum. 



15. Orthoceras Nicholiantjm. — From the Lower Ludlow rocks, Usk. In the —%8 



Museum of the Cardiff Naturalists' Society. 



