Inframedian

The inframedian zone ranges from fifty fathoms to a hundred.

Thus, in the British seas naturalists speak of a littoral, laminarian, coralline, and coral zone; an in the ocean genrally, of a littoral, circum-littoral, median, inframedian, and abyssal or deep-sea zone.

Thus the upper, inframedian and carinal laterals have three layers, but the rostrum and rostro-laterals, which appear at a later stage, have only two.

Gl. oculatum is easily distinguished from these by the fact that it bears no spines and by the median rather than inframedian girdle.

From the ventral apices of the two lateral cartilages, the two inframedian radular tensors run upwards and slightly forwards.

Oogonium with projections or lateral pleating of the wall (flange ) ; circumcision supramedian , median , submedian or distinctly inframedian, sometimes resembling a hinged pore.