Spiny Dog-Fishes, [455]

Spiracle, [279], [283]

Spiracular pseudobranch, [279], [284];

in Teleostomi, [284];

blood supply, [335]

Spiral valve, [264] f.

Spix, [558] n.

Spleen, [342]

Spoon-Bill, [491]; = Polyodon, q.v.

Sprat, [564]