22. A. Outline of Skull and Cranial Elements of Erpelosaurus minutus Moodie, from the Cannelton Slates of Pennsylvania 99 B. Outline of Skull and Cranial Elements of Erpetosaurus radiatus Cope, from the Coal Measures of Linton 99 C. Palate of Erpetosaurus (tabulatus?), from the Coal Measures of Linton, Ohio 99 D. Outline of Skull and Cranial Elements of Erpetosaurus acutirostris Moodie, from the Coal Measures of Linton, Ohio 99 E. Outline of Larger Part of Skeleton of Odonterpeton triangularis Moodie, from the Coal Measures of Linton, Ohio 99 F. Right Mandible of Erpetosaurus tabulatus Cope, from the Linton, Ohio, Coal Measures 99 G. Skull Elements and Lateral-line Canals of Erpetosaurus tabulatus Cope, from the Coal Measures of Linton 99 23. Skull of Stegops divaricata 113 24. Microsaurian Skulls from Linton, Ohio: A, Diceratosaurus lævis; B, Diceratosaurus robustus 119 25. Restoration of Eoserpeton 124 26. Restoration of Amphibamus 128 27. Skeleton of Amphibamus grandiceps 129 28. Probable Appearance of Amphibamus 130 29. Skeleton of Cephalerpeton 133 30. Restoration of Ptyonius 140 31. Restoration of Œstocephalus 144 32. Vertebræ of Molgophis brevicostatus 148 33. Fore-limb of a Member of the Molgophidæ, Possibly Pleuroptyx 152 34. A. Interclavicle of Sauropleura pauciradiata 159 B. Left Clavicle of Sauropleura pauciradiata 159 35. Skull and Skeleton of Saurerpeton latithorax 164 36. Mandible of Leptophractus dentatus 169 37. So-called Interclavicle of Eurythorax sublævis 170 38. Skeletal Elements of Amblyodon 177 39. Vertebra of Spondylerpeton spinatum 179 40. Mandible of Macrerpeton deani 184 41. Vertebræ of Eosaurus acadianus: A, Oblique Lateral View; U, Oblique View; C, Posterior View; D, Transverse Section; E and F, Microscopic Sections 188 42. Skull and Mandible of Eobaphetes kansensis: A, Outer View of Mandible; B, Portion of Skull; C, Inner Surface of Mandible 191 43. Footprints of Dromopus agilis 200