Paleontological report containing an examination of an ancient species of stock oyster and four separate successional species of oyster that resulted from that stock. This example is presented under the successional mode of speciation of Julian Huxley.

Abstract: "Gravitational observations were made of the pre-Cambrian Coal Creek serpentine mass in Blanco and Gillespie Counties, Texas, the geology of which had been mapped previously. The observed gravitational anomalies indicate roughly the depth of the serpentine mass below which it may possibly grade into its parent peridotitic rock. Probable correlation between the gravitational map and the other geologic features of the area is indicated" (p. 151).