In the beginning of January 1865, the author received from the Rev. Alexander Robb, Old Calabar, a package of specimens of natural history preserved in spirits. Among these were two small ganoid fish. They were, however, imperfect, having been torn across near the anal region, and their caudal extremities were wanting. The characters of the fish could not, therefore, be completely determined. The author, however, exhibited them at a meeting of the Royal Physical Society, on the 22d March 1865, and stated that they were allied to the genus Polypterus; but from various differences in character, to be afterwards detailed, and especially the great relative length of their bodies, and the apparently total absence of ventral fins, he would place them provisionally in a new genus, which, from their general aspect and form, he designated Erpetoichthys, the reptile or serpent fish; and the species, from the locality where it was found, he named E. Calabaricus.