IT may interest some of your readers to know that I have lately received another specimen of this rare fish from my friend Dr. J. Barbosa Rodriguez, the energetic Director of the Museu Botanico do Amazonas at Manaos. This is the fifth specimen known. A short notice of the fourth specimen, an adult female of large size, caught in the Igarape do Aterro near Manaos, also presented to me by Dr. Barbosa Rodriguez, appeared in NATURE more than a year ago (vol. xxxv. p. 343). Dr. Rodriguez published a note on that specimen in the Jornal do Commercio of Rio de Janeiro for October 15, 1886. I state this as his note might easily be overlooked, not having appeared in a scientific periodical.