'58, 



PAL.EONTOLOGY 



FIG. 46. APERTCRAL MARGINS OF CEPHALOPODA. 



a, a', Phylloceras mediterraneum Neumayr, Vesulian, near Digne (Basses 



' Alpes). (X J.) Showing rostrum and lappets (unusual in Phyllocera- 



tida) and a number of varices, only parallel to apertural margin if 



