An early Cretaceous marine algal floral consisting of Boueina pygmaea Pia, Neomeris pfenderae, n. sp., Arcicularia americana, n. sp., and Archaeolithothamnium? sp. is described from the Mural Limestone of Cochise County. A study of known occurrences of Neomeris suggests that Recent species of this genus are and Cretaceous species were, restricted to tropical marine environments (isocrymes above 20 degrees C.) within the lower littoral and upper infralittoral zones (O to 10 m.).