A strange arthropod from the Mazon Creek of Illinois and the Trans Permo-Triassic Merostomoidea (Trilobitoidea) / [by] Frederick R. Schram --

v.20:no.6(1971)

A new and primitive early Oligocene horse from Trans-Pecos Texas / Paul O. McGrew, Dept. of Geology, The University of Wyoming.

v.10:no.15(1953)