Age, 11.5 days.

Standard length, 3.95 mm.

Length of caudal fin, 0.63 mm. Mesencephalon width, 1.03 mm. Depth of yolk, 1.33 mm.

Internally, there is little difference be-tween this stage and the previous one. The head protrudes out of the extra-embryonic membranes so that the anterior margin of the pericardial serosa encircles the head at the level of the lens.