branchia

Why none of us started specialising branchiae I do not know, but feel that would have been the proper sort of breathing apparatus for such an atmosphere.

Gills or branchiae may be developed by parts of an appendage becoming thin-walled and vascular and either expanded into a thin lamella or ramified.

Head very large, not marked off from the body; neither branchia nor suckers; fins situated near the middle of the body.

It is probable that the Silurian scorpion was an aquatic animal, and that its respiratory lamellae were still projecting from the surface of the body to serve as branchiae.

The appendages of the body are reduced to branchiae, present in certain forms.