Dictionary.net

• The closing subdivision of the Devonian age in America. The rocks of this period are well developed in the Catskill mountains, and extend south and west under the Carboniferous formation. See the Diagram under Geology.

2010 - New Age Dictionary Database
By Oddity Software

• The closing subdivision of the Devonian age in America. The rocks of this period are well developed in the Catskill mountains, and extend south and west under the Carboniferous formation. See the Diagram under Geology.

1913 - Webster's Revised Unabridged Dictionary
By Noah Webster.