Biology of Finfish and Shellfish

4.11.7. 5^th Stage

The arms shift still nearer to one another (i.e. towards the axis of the embryo), grouping below the rudiments of the head (which have become fused), and form a somewhat narrow circle on the ventral side in such a way that, when the embryo is seen from the dorsal side, some of them are hidden by the head. As a consequence of this, the embryo, which is already recognizable as young Sepia, now becomes sharply constricted from the yolk beneath it. The free edges of the rudiments of the funnel fuse and move to a position within the mantle cavity.