The Collaborative International Dictionary
Pteryla
Pteryla \Pte*ry"la\, n.; pl. Pteryl[ae]. [NL., fr. Gr. ? feather + ? wood, forest.] (Zo["o]l.) One of the definite areas of the skin of a bird on which feathers grow; -- contrasted with apteria.
Wiktionary
pteryla
n. (context ornithology English) One of the areas of a bird's skin on which feathers grow.