PLATE II (continued). 



Fig. 



23. Camarophoria Schlotheimi, V. Buck. Internal cast, seen from the beak, to show the muscular 



impressions, as in fig. 11. Humbleton hill. 



24. — — Interior of the ventral valve, enlarged, minus the marginal expansions. 



Tunstall hill. Collection of Mr. Howse. 



25. — — Fragment, considerably enlarged, to show the hinge and other internal 



processes, from a very perfect example in the collection of Mr. Howse. 

 Tunstall bill. 



26. — — Another fragment, seen more in front. 



27. — — Profile section, to show the position of the different parts. Tunstall hill. 



28. — globulina, Phillips. Natural size. Tunstall hill. Collection of Mr. Kirkby. 



29. 30. — — Two other examples (enlarged), with two and three ribs on the mesial 



fold. Tunstall hill. 

 31. — — A fragment of the interior, enlarged, in the collection of Mr. Kirkby. 



Humbleton hill. 

 32 — 36. Streptorhynchus pelargonatus, Schloth. Different specimens and variations in shape, from 



Tunstall and Humbleton hills, in the collections of Messrs. Howse 



and Kirkby. 



37. — — A specimen from Dalton, in the collection of Mr. Howse (enlarged). 



38. — — Interior of the dorsal valve, enlarged. Tunstall hill. Collection of 



Mr. Howse. 



39. — — Dorsal valve, seen from the umboue, to show the bifid cardinal process. 



Tunstall. Collection of Mr. Kirkby. 



40. — — Interior of the ventral valve. Tunstall. Collection of Mr. Howse. 



41. — — Interior of the ventral valve, seen under the area, to show the rudimen- 



tary dental or rostral plates. 



42. — — Internal cast of the ventral valve, showing the position and shape of the 



muscular scars ; from Tunstall hill. Collection of Mr. Kirkby. 



