Myers, G. S. (1944). Two extraordinary new blind nematognath fishes from the Rio Negro, representing a new subfamily of Pygidiidae, with a rearrangement of the genera of the family, and illustrations of some previously described genera and species from Venezuela and Brazil. <em>Proceedings of the California Academy of Sciences (Series 4).</em> 23 (40): 591-602, Pls. 52-56.