162 



PALAEONTOLOGY 



FIG. 47. SEPTAL SUTURES OF EARLY AMMONOIDEA. 



Each figure has the umbilical margin on the left and the middle line of the 

 periphery on the right. The arrow points towards the body-chamber. 

 a, Anarcestes, Devonian ; b, Manticoceras, Devonian ; c, Tornoceras, 

 Devonian; d, Gastrioceras, Carboniferous; e, Prolecanitts , Carboni- 

 ferous ; f, Medlicotta, Permian ; g, Paraceratites, Triassic ; A, Phyl- 

 loceras, Jurassic, a-/, After Crick ; g, after Perrin Smith ; A, after 

 d'Orbigny. 



