Describe the differences in internal morphology that can be seen between a Nautilus and Ammonite

in nautiloids septal necks are retrosiphonate (point towards the protoconch / centre OR away from the aperture)in ammonoids septal necks are mainly prosiphonate (point towards the aperture OR away from the protoconch / centre)
in nautiloids, the siphuncle is centralin ammonoids, the siphuncle is ventral (positioned towards the outer margin / marginal / towards the edge)