Defn: A genus of Devonian fossil fishes with winglike appendages. The head and most of the body were covered with large bony plates. See Placodermi.

PTERIDOLOGIST
Pter`i*dol"o*gist, n.

Defn: One who is versed in pteridology.

PTERIDOLOGY
Pter`i*dol"o*gy, n. Etym: [Gr. -logy.]

Defn: That department of botany which treats of ferns.

PTERIDOMANIA
Pter`i*do*ma"ni*a, n. Etym: [Gr. mania.]

Defn: A madness, craze, or strong fancy, for ferns. [R.] C. Kingsley.

PTERIDOPHYTA
Pter`i*doph"y*ta, n. pl. Etym: [NL., from Gr. (Bot.)

Defn: A class of flowerless plants, embracing ferns, horsetails, club
mosses, quillworts, and other like plants. See the Note under
Cryptogamia.
— Pter"i*do*phyte`, n.

Note: This is a modern term, devised to replace the older ones acrogens and vascular Cryptogamia.