IT seems worth while to make a special note of the occurrence of the above-named food-fish in the inland waters of Ceylon. Its near ally, Mastacembelus armatus, has long been known to occur here. The general Ceylonese term for fishes belonging to the family Rhynchobdellidæ, commonly known as “spined” or “thornybacked eels,” though not nearly related to the true eels, is “telliya,” but the natives distinguish between the “Gangtelliya” (river-telliya), which is Mastacembelus armatus, and the “Batakola-telliya” (alluding to the lanceolate form of the body), which is Rhynchobdella aculeata. The latter is reputed to grow to a length of 15 inches, and I recently examined one of 12 inches. In the former, commoner species, the vertical fins are confluent and the dorsal spines are numerous (about thirty-eight); in the second species, which has not previously been recorded from Ceylon, the dorsal and anal fins are separated from the caudal by a notch above and below; the dorsal spines are less numerous (sixteen), and the long, fleshy snout, which gives these fishes such a remarkable, antiquated appearance, is transversely ribbed below. The identification is therefore not open to doubt.