George Leo Haydock, on Gen 1:20

“God also said: Let the waters bring forth the creeping creature having life, and the fowl that may fly over the earth under the firmament of heaven.”

“Creeping: destitute of feet like fishes, which move on their bellies. (Menochius) — Fowl. Some assert that birds were formed of the earth, but they seem to have the same origin as fishes, namely, water; and still they must not be eaten on days of abstinence, which some of the ancients thought lawful, Socrates v. 20. To conciliate the two opinions, perhaps we might say, that the birds were formed of mud, (Calmet) or that some of the nature of fish, like barnacles, might be made of water and others of earth. (Chap. 11. 19.[ii. 19.?]) — Under: Hebrew: on the face of the firmament, or in the open air. (Haydock)”

Imported from an open dataset — not yet checked against the printed edition.