Ludwig, H. (1894). The Holothurioidea. In: Reports on an exploration off the west coasts of Mexico, Central and South America, and off the Galapagos Islands, in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer "Albatross," during 1891, Lieut. Commander Z. L. Tanner, U. S. N., commanding. XII. Memoirs of the Museum of Comparative Zoölogy at Harvard College. 17(3): 183 pp., 19 pls.
The Holothurioidea. In: Reports on an exploration off the west coasts of Mexico, Central and South America, and off the Galapagos Islands, in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer "Albatross," during 1891, Lieut. Commander Z. L. Tanner, U. S. N., commanding. XII.
Memoirs of the Museum of Comparative Zoölogy at Harvard College
