Calycida and Orycea. Lower Cretaceous. Beremian. Holes, Claps, mails and gunshots. Middle Cret. - Cenomanian, Turonian are some Albian. Ornithostyl gray li. often mag. but not aldomite. Many foots, much metamorphed. Maximum of sea invasion. Mexico an archipelago. general elevation set in with Anti-continuing. Continues into Upper Cret. Upper Cret. Some Albian and are Danian. Found only in N.E. Mexico. Julius bandstones with gray to black shales. Retreating sea. Sierra Madre of east and west coast acquired at this time. Mexico then had its present outline. Eocene. More critical elevations, increase of territory. Miocene. Invasion of the sea along east coast. Also W. coast and origin of San Cal.