Defn: A division of gastropod Mollusca, including the chitons. The back is covered by eight shelly plates. Called also Polyplacophora. See Illust. under Chiton, and Isopleura.

PLAGA
Pla"ga, n.; pl. Plagæ. Etym: [L. plaga a blow, a welt, a stripe.]
(Zoöl.)

Defn: A stripe of color.

PLAGAL
Pla"gal, a. Etym: [F., from Gr. (Mus.)

Defn: Having a scale running from the dominant to its octave; — said of certain old church modes or tunes, as opposed to those called authentic, which ran from the tonic to its octave. Plagal cadence, a cadence in which the final chord on the tonic is preceded by the chord on the subdominant.

PLAGATE
Pla"gate, a. (Zoöl.)

Defn: Having plagæ, or irregular enlongated color spots.

PLAGE
Plage, n. Etym: [F., fr. L. plaga.]

Defn: A region; country. [Obs.] "The plages of the north." Chaucer.

PLAGIARISM
Pla"gia*rism, n. Etym: [Cf. F. plagiarisme.]