Biology of Finfish and Shellfish

4.11.6. 4^th Stage

The visceral dome projects further, and have a free mantle edge all round its base. The gills have shifted further into the mantle cavity, which is now larger, and lies posteriorly. The rudiments of the funnel also now lie close to the mantle. The rudiments of the arms have shifted from behind further forward round the rudiments of the head. As the whole embryo projects more distinctly from the yolk, the rudiments of the arms shift near to one another and under the rudiments of the head. The anus is already covered by the mantle fold.