VI LIST OF ENGRAVINGS. 



Plate 



25'. Fossil Crocodileans and Chelonian. 



26. Footsteps on Red Sandstone near Dumfries. 



26'. Footsteps on Red Sandstone at Hessberg, (Double Plate.) 

 26". Hind footstep of Chirotherium on Sandstone from Hessberg. 

 26'". Footsteps of some unknown Reptile on Sandstone from 



Hessberg. 

 26"' Several species of Ornithichnites on Sandstone in the valley 



of the Connecticut, (Double Plate.) 

 26''- Ornithichnites Giganteus, on Sandstone from Connecticut. 



27. Scales, Jaw, and Teeth of fossil Fishes. 

 27*- Recent and fossil Sauroid Fishes. 



27''" Fish from the Coal Formation at Saarbriick. 



27*^- Fish from the Oolite Formation. 



27**- Jaws, Teeth, and Spine of Recent and Fossil Sharks. 



27''' Teeth on the Palate of Acrodus nobilis. 



27^- Teeth of Ptychodus polygyrus. 



28. Pens and Ink Bag of recent and fossil Loligo. 



29. Fossil Pens and Ink Bags of Loligo, from the Lias. 



30. Large fossil Pen of Loligo, from the Lias. 



31. Nautilus Pompilius with its animal ; and Rhyncholites. 



32. Chambers and Siphuncle of Nautilus Hexagonus. 



33. Chambers and Siphuncle of Nautilus Striatus. 



34. Animal of Nautilus Pompilius. 



35. Exterior of Ammonites Obtusus. 



36. Chambers and Siphuncle of Ammonites Obtusus. 



37. Various forms of Mechanism to strengthen Ammonites. 



38. Lateral view of Ammonites Heterophyllus. 



39. Longitudinal view of Ammonites Heterophyllus. 



40. Ammonites Henslowi ; A. Nodosus ; A. Sphaericus, and 



A. Striatus. 



41. Chambers of Ammonites Giganteus. 



42. Chambers and Siphuncle of Nautilus and Ammonite. 



43. Nautilus Sypho, and N. Zic-Zac. 



44. Chambered Shells allied to Nautilus and Ammonite. 

 44'. Illustrations of the Genus Belemnosepia. 



44". Ink Bags of Belemnosepia. 



45. Trilobites and recent animals allied to them. 



46. Various forms of Trilobites. 



