The new species Lithostrotion (Siphonodendron) oculinum, Aulina semimuralis, and Aulina occidentalis are described from northern Arizona. L. (S.) oculinum is a reliable marker in the upper part of the Redwall Limestone in beds thought to be of late Osage or early Meramec age. The 2 Aulina species constitute the first authenticated record of this genus in North America. They occur in a residual deposit derived from Mississippian rocks during development of the post-Redwall karst topography and are thought to represent a horizon of Meramec or Chester age.

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