x LIST OF ILLUSTRATIONS 



FIG. PAGE 



30. Rimella fissurclla - 103 



31. Trivia avellana - - 105 

 32.' Fusus porrccius - - 107 



33. Planorbis discus - - 108 



34. Gastropods - 114 



35. Gastropods - 118 



36. Orthoceras - 125 



37. Nautilus albensis - 1 27 



38. Nautilus excavatus - 128 



39. Asteroccras obtusuin - 131 



40. Telramerocems obovatum - 137 



41. Cephalopod Coiling Cycle - 141 



42. Manticoccras aff. retrorsnin - 152 



43. Manticoccras rliyncliostonia - 153 



44. Gaslrioceras carbonari it in - 155 



45. Apertural Margins of Cephalopoda -- . - 156 



46. Apertural Margins of Cephalopoda - 158 



47. Septal Sutures of Early Ammonoidea - - 162 



48. Septal Sutures of Jurassic and Cretaceous Ammonoidea 164 



49. Whorl-shape in Ammonoidea - - 166 



50. Lunuloceras brighti - 176 



51. Olcostephanus astierianus - 178 



52. Mortoniceras inflatum - - 180 



53. Belemnites - 185 



54. Belemnites - 188 



55. Calymene blumenbachi - - 195 



56. Dalmanitcs caudaius - - 199 



57. Triarthrus becki - - 201 



58. Trinucleus concentricus - - 203 



59. Trilobites - 208 



60. Clieirurus bimucronaliis - 210 



61. Hypostomes of Various Trilobites - 211 



62. Lauarkia spinosa - 223 



63. Fish Teeth and Scales - - 224 



64. Tooth Structure - - 226 



65. Caudal Fins - 228 



66. Fins and Limbs - - 232 



