"56 S. proavita.
Robust, pointed; 1.40 by 55; margin. .10: frontal bar, not well developed; costae, 24 narrower than interspaces. Goat Key, Great Harbor; fossil in cliff at north end of key . 40. Plate 26, figs. 9, 10." (Maynard and Clapp in Maynard, 1921a:129)