FAMILY 82.-NOTOPTERIDA. (1 Genus, 5 Species.)

"Fresh-water fishes, without barbels, head and body scaly, long tapering tail, and short posterior dorsal fin."

DISTRIBUTION.-Rivers of India, Siam, the Sunda Islands, and West Africa.

FAMILY 83.-HALOSAURIDÆ. (1 Genus, 1 Species.) “Marine fishes, with cycloid scales, a short median dorsal fin, and no barbels."

DISTRIBUTION.-Deep waters of the Atlantic, Madeira.

FAMILY 84.-GYMNOTIDÆ. (5 Genera, 20 Species.) "Fresh-water fishes, with elongate bodies, pointed tail, and no dorsal fin."

DISTRIBUTION.-Tropical America from Trinidad to the River

Parana.

The genera are distributed as follows:

Sternarchus (8 sp.), Guiana and Brazil; Rhamphichthys (6 sp.), Guiana and Brazil; Sternophygus (4 sp.), Tropical America; Carapus (1 sp.), Trinidad to Brazil; Gymnotus, (1 sp. -the Electric eel), Tropical South America.

FAMILY 85.-SYMBRANCHIDE.

(4 Genera, 6 Species.)

"Marine and fresh-water fishes, having elongate bodies without fins, and very minute scales or none."

DISTRIBUTION.-Fresh waters and coasts of Western Australia and Tasmania.

The genera are:

Amphipnous (1 sp.), Bengal; Monopterus (1 sp.), Siam to Northern China and Sunda Islands; Symbranchus (3 sp.), Tropical VOL. II.-30

America, and India to Australia; Chilobranchus (1 sp.), Australia and Tasmania,

FAMILY 86.-MURÆNIDÆ. (26 Genera, 230 Species.)

"Marine or fresh-water fishes, with cylindrical or band-like bodies and no ventral fins."

DISTRIBUTION.-The seas and fresh waters of temperate and tropical regions. This family is divided by Dr. Günther into two sub-families and nine sections. The genus Anguilla, comprising our common Eel and a number of species from all parts of the world, is the only one which is found in fresh water, though even here most of the species are marine. Anguilla and Conger are the only British genera.

FAMILY 87-PEGASIDE. (1 Genus, 4 Species.)

"Small marine fishes, covered with bony plates, and short opposite dorsal and anal fins.”

DISTRIBUTION.-Indian Ocean and seas of China and Aus

tralia.

Order V-LOPHOBRANCHII.

"Fish with a segmented bony covering, long snout, and small toothless mouth."

FAMILY 88.-SOLENOSTOMIDE. (1 Genus, 3 Species.)

"Marine Lophobranchii, with wide gill openings and two dorsal fins."

DISTRIBUTION.-Indian Ocean, from Zanzibar to China and

the Moluccas.

FAMILY 89.-SYNGNATHIDE. (15 Genera, 112 Species.) "Marine Lophobranchii, with very small gill opening and one soft dorsal fin."

DISTRIBUTION.-All the tropical and temperate seas. Some species of Syngnathus, Doryichthys, and Clonotus enter fresh water, and a few live in it exclusively. Siphonostoma, Syngnathus, Nerophis, and Hippocampus are British genera. The Hippocampina (5 genera, 25 sp.), or Sea-horses, are peculiar to the Indian and Pacific Oceans, except three or four species of Hippocampus in the Atlantic and Mediterranean.

Order VI-PLECTOGNATHI.

"Fishes covered with rough scales or shields, having a narrow mouth, and soft posterior dorsal fin."

FAMILY 90.-SCLERODERMI. (7 Genera, 95 Species.) "Marine Plectognathi, with toothed jaws."

DISTRIBUTION.-Temperate and Tropical seas, but much more abundant in the Tropics.

FAMILY 91.—GYMNODONTES. (10 Genera, 82 Species.) "Marine or fresh-water Plectognathi, with jaws modified into a beak."

DISTRIBUTION.—Temperate and tropical regions.

Some species of Tetrodon are found in the rivers of Tropical America, Africa, and Asia. Species of Tetrodon and Orthagoriscus have been found on the British coasts.

SUB-CLASS II.--DIPNOI.

FAMILY 92.-SIRENOIDEI. (3 Genera, 3 Species.)

"Eel-shaped fresh-water fishes, covered with cycloid scales; the vertical fins forming a continuous border to the compressed tapering tail."

DISTRIBUTION.—Rivers of Tropical Africa, South America, and

Australia.

The genera are:-Protopterus (1 sp.), Tropical Africa; Lepidosiren (1 sp.), Amazon Valley; Ceratodus (1 sp.), Queensland.

SUB-CLASS III.—GANOIDEI.

Order I-HOLOSTEI

"Body covered with scales."

FAMILY 93.—AMIIDE. (1 Genus, 1 Species.)

"A fresh-water fish, with cycloid scales and a long soft dorsal fin."

DISTRIBUTION.-United States.

FAMILY 94.-POLYPTERIDÆ. (2 Genera, 2 Species.) Fresh-water fishes, with ganoid scales and dorsal spines." DISTRIBUTION.-Central and Western Africa.

The genera are :—

Polypterus (1 sp.), the Nile and rivers of West Africa; Calamoichthys (1 sp.), Old Calabar.

FAMILY 95.-LEPIDOSTEIDÆ. (1 Genus, 3 Species.)

"Fresh-water fishes, with ganoid scales, and dorsal and anal fins composed of articulated rays.”

DISTRIBUTION.-The genus Lepidosteus, the Garfishes or Bony Pikes, inhabits North America to Mexico and Cuba.

Order II-CHONDROSTEI.

Sub-cartilaginous scaleless fishes with heterocercal tail, the skin with osseous bucklers or naked."

FAMILY 96.-ACCIPENSERIDE. (2 Genera, 20 Species.) "Marine or fresh-water fishes with osseous bucklers and inferior mouth."

DISTRIBUTION.-Temperate and Arctic regions of the northern hemisphere. Accipenser (19 sp.), comprising the Sturgeons, has the distribution of the family; most of the species are marine, but some are confined to the Caspian and Black Seas and the great American lakes with the rivers flowing into them, while the Danube, Mississippi, and Columbia River have peculiar species. The other genus, Scaphirhynchus (1 sp.), is confined to the Mississippi and its tributaries.

FAMILY 97.-POLYDONTIDÆ. (1 Genus, 2 Species.) "Fresh-water fishes, with wide lateral mouth and naked

skin."

DISTRIBUTION.—The Mississippi and Yang-tse-kiang rivers.