Inter-renal bodies, [346], [346]

Intromittent organs, [414]

Ipnops, [611], [613];

I. murrayi, [612];

photophore, [179]

Iridocytes, [166]

Ischnacanthus, [441]

Ischyodus, [474]

Isichthys, [551]

Iso, [639]