Anderson, F. M., 1929. Marine Miocene and Related Deposits of North Colombia. Proceedings of the California Academy of Sciences, ser. 4. vol. 18 (4 ): 73 -213 . (1.69 MB)
New Species-Group Names:
crenospiratus Anderson, 1929. p 112 pl. ix f. 6. 7.
tuberacola Anderson, 1929. p. 112. pl. ix. f. 4. 5.