[12] Heterocercal.
[13] Acipenser sturio.
[14] Isinglass is made from the covering of this air-bladder.
[15] Lepidosteus.
[16] Polypterus.
[17] Amia.
[18] Lepidosiren.
[19] Protopterus.
[20] Ceratodus.
[21] These fish, coiled round, may be seen in the British Museum.