The normal development of this cephalopod has been divided into 30 stages based on morphological criteria. The 1st 3 stages include maturation divisions and the 4th stage is 1st cleavage. Stage 5 has 2 cells and stage 9, 64 cells. At stage 10 the blastoderm is well established and by stage 16 about two-thirds of the egg surface is cellulated. During stages 17 and 18 the major organ primordia appear. In stage 19 invagination of the mouth and eyes begins. At stage 21 the eye vesicles are completely closed and the sucker primordia are evident on the arms. In stage 23 the mantle covers about one-half of the gills. Pigmentation first appears in the eyes and chromatophores during stage 26. The secondary cornea completely covers the eye at stage 28 and hatching occurs at stage 30. A plot of developmental age versus chronological age is included as well as one labeled diagram and drawings of each stage.