FAMILY 55.—OPHIDIIDÆ. (16 Genera, 43 Species.)

"Marine fishes, with more or less elongate bodies, the dorsal and anal fins united, and the ventral fins rudimentary or absent."

DISTRIBUTION.-Almost universal; from Greenland to New Zealand, but most abundant in the Tropics.

Ophidium and Ammodytes occur in British seas; Lucifuga inhabits subterranean fresh waters in Cuba.

FAMILY 56.-MACROURIDE. (3 Genera, 21 Species.)

"Marine fishes, with the body terminating in a long, compressed tapering tail, and covered with spiny, keeled or striated scales."

DISTRIBUTION.-North Atlantic from Greenland to Madeira and the Canary Islands, Mediterranean, Japanese and Australian

seas.

None of these fishes have occurred in the British seas.

FAMILY 57.-ATELEOPODIDÆ. (1 Genus, 1 Species.) "Marine fishes, with the naked body terminating in a long compressed, tapering tail.”

DISTRIBUTION.-Japan.

FAMILY 58.-PLEURONECTIDA. (34 Genera, 185 Species.)

"Marine.carnivorous fishes, with strongly compressed flat bodies, one side of which is colourless, and eyes unsymmetrically placed, both on the coloured side. They inhabit the sandy bottoms of shallow seas, and often ascend rivers."

DISTRIBUTION.—Universal, on Arctic, Temperate, and Tropical

coasts.

Seven genera occur in British seas, viz.: Hippoglossus, Hippoglossoides, Rhombus, Phrynorhombus, Arnoglossus, Pleuronectes (Turbot), and Solea (Sole). There are 13 genera in the Atlantic and 23 in the Pacific, 4 being common to both; and 2 found only in the Mediterranean. A Pacific genus, Synaptura, has one species in the Mediterranean.

Order IV-PHYSOSTOMI

FAMILY 59.-SILURIDE. (114 Genera, 547 Species.) "Fresh-water or marine, scaleless fishes, often with bony shields, and the head always furnished with barbels."

DISTRIBUTION.-The fresh waters of all the temperate and tropical regions, those which enter the salt water keeping near the coast.

This extensive family is divided by Dr. Günther into eight sub-families and seventeen groups, the distribution of which is as follows:

:

Sub-family 1 (SILURIDE HOMALOPTERÆ) is confined to the Old World. It consists of three groups: Clarina (2 genera, Clarias and Heterobranchus) ranges over the whole area of the Ethiopian and Oriental regions, to which it appears to be strictly confined; Plotosina (3 genera, Plotosus, Copidoglanis, and Cnidoglanis) ranges from the eastern coasts of Africa to Japan, Polynesia, and Australia, in seas and rivers; Chacina (1 genus, Chaca) ranges from India to Borneo.

Sub-family 2 (SILURIDE HETEROPTERA) is also confined to the Old World; it consists of one group,-Silurina, containing 19 genera, viz. :-Saccobranchus (4 sp.), India to Cochin China and Ceylon; Silurus (5 sp.), Palæarctic region from Central Europe to Japan, China, and Afghanistan, and a species in Cochin China; Silurichthys (3 sp.), Cashmere, Java, and Borneo; Wallago (2 sp.), Hindostan, Sumatra, and Borneo; Belodontichthys (1 sp.), Sumatra and Borneo; Eutropiichthys (1 sp.), Bengal; Cryptopterus

(15 sp.), Java, Sumatra, and Borneo, with a species in the Ganges, in Siam, and (?) in Amboyna; Callichrous (10 sp.), Afghanistan to Borneo and Java; Schilbe (5 sp.), Tropical Africa; Eutropius (6 sp.), Tropical Africa and Central India; Hemisilurus (2 sp.), Java and Sumatra; Siluranodon (1 sp.), Nile; Ailia (2 sp.), Bengal; Schilbichthys (1 sp.), Bengal; Laïs (1 sp.), Java, Sumatra, Borneo; Pseudeutropius (6 sp.), India and Sumatra; Pangasius (7 sp.), Ganges, Sumatra, Java, Borneo; Helicophagus (2 sp.), Sumatra; Silondia (1 sp.), Ganges.

Sub-family 3 (SILURIDA ANOMALOPTERA) is confined to Equatorial America; it consists of the group Hypopthalmina, containing 2 genera: Helogenes (1 sp.), Hypopthalmus (4 sp.), from the country north of the Amazon, Surinam, and the Rio Negro.

Sub-family 4 (SILURIDE PROTEROPTERA) ranges over all the tropical and most of the temperate parts of the globe, except Europe and Australia. It consists of four groups: Bagrina (16 genera), ranging over most of the Old World and North America; Pimelodina (15 genera), confined to Tropical America, except one genus which is African; Ariina (10 genera), all Tropical regions; and Bagarina (3 genera), Oriental region. The distribution of the genera is as follows:

Bagrus (2 sp.), Nile; Chrysichthys (5 sp.), Tropical Africa; Clarotes (1 sp.), Upper Nile; Macrones (19 sp.), India, Ceylon to Borneo, and one species in Asia Minor; Pseudobagrus (4 sp.), Japan, China, and Cochin China; Liocassis (5 sp.), Japan, China, Java, Sumatra, and Borneo; Bagroides (3 sp.), Sumatra and Borneo; Bagrichthys (1 sp.), Sumatra and Borneo; Rita (5 sp.), Continental India and Manilla; Acrochordonichthys (6 sp.), Java and Sumatra; Akysis (3 sp.), Java and Sumatra ; Olyra (1 sp.), Khasya; Branchiosteus (1 sp.), Khasya; Amiurus (13 sp.), Nearctic region to Guatemala and China; Hopladelus (1 sp.), North America; Noturus (4 sp.), North America; Sorubim (1 sp.), Amazon; Platystoma (11 sp.), Tropical South America; Hemisorubim (1 sp.) Rio Negro, Brazil; Platistomatichthys (1 sp.), Rio Branco, Brazil; Phractocephalus (1 sp.), Amazon; Piramutana (2 sp.), Equatorial America; Platynematichthys

(1 sp.), northern and southern tributaries of Amazon; Piratinga (3 sp.), Amazon Valley; Sciades (2 sp.), Amazon; Pimelodus (42 sp.), Mexico to La Plata, single aberrant species from West Africa, Java and the Sandwich Islands; Pirinampus (1 sp.), Brazil; Conorhynchus (1 sp.), Brazil; Notoglanis (1 sp.), Madeira, Amazon Valley; Callophysus (3 sp.), Tropical South America; Auchenaspis (1 sp.), Tropical Africa; Arius (68 sp.), all Tropical regions; Galeichthys (1 sp.), Cape of Good Hope; Genidens (1 sp.), Brazil; Hemipimelodus (3 sp.), India, Sumatra, and Borneo; Ketingus (1 sp.), Sunda Islands; Elurichthys (4 sp.), Eastern United States to Guiana; Paradiplomystax (1 sp.), Brazil; Diplomystax (1 sp.), Chili; Osteogeniosus (3 sp.), India to Java; Batrachocephalus (1 sp.), Java and Sumatra; Bagarius (1 sp.), India to Java; Euclyptosternum (1 sp.), India; Glyptosternum (8 sp.), Himalayas, Central India, Java, and Sumatra; Hara (3 sp.), Continental India; Amblyceps (3 sp.), Continental India.

Sub-family 5 (SILURIDE STENOBRANCHIA) is confined to South America and Africa, with one genus and species in the Ganges. It consists of three groups: Doradina (12 genera), South America and Africa; Rhinoglanina (3 genera), Central Africa and the Ganges; Malapterurina (1 genus), Tropical Africa. The distribution of the genera is as follows:

Ageniosus (4 sp.), Surinam to La Plata; Tetranematichthys (1 sp.), Central Brazil, Rio Guaporé; Euanemus (1 sp.), Surinam and Brazil; Auchenipterus (9 sp.), Equatorial America; Centromochlus (2 sp.), Equatorial America; Trachelyopterus (2 sp.), Equatorial America; Cetopsis (3 sp.), Brazil; Asterophysus (1 sp.), Rio Negro, North Brazil; Doras (13 sp.), Tropical South America east of Andes; Oxydoras (7 sp.), Amazon Valley and Guiana; Rhinodoras (3 sp.), Tropical South America east of Andes; Synodontis (12 sp.), Tropical Africa; Rhinoglanis (1 sp.), Upper Nile; Mochocus (1 sp.), Nile; Callomystax (1 sp.), Nile; Malapterurus (3 sp.), Tropical Africa.

Sub-family 6 (SILURIDE PROTEROPODES) inhabits Tropical America and Northern India as far as Tenasserim. It consists of two groups: the Hypostomatina (17 genera), with the same distribution as the sub-family, and the Aspredinina (3 genera),

confined to Equatorial America. The distribution of the genera is as follows:

Arges (2 sp.), Andes of Peru and Ecuador; Stygogenes (2 sp.), Andes; Brontes (1 sp.), Andes; Astroblepus (1 sp.), Popayan; Callichthys (11 sp.), Tropical South America east of Andes, and Trinidad; Plecostomus (15 sp.), Tropical South America east of Andes, and Trinidad; Liposarcus (3 sp.), Surinam and Brazil; Chatostomus (25 sp.), Tropical America, Trinidad, and Porto Rico; Pterygoplichthys (4 sp.), Brazil; Rhinelepis (1 sp.), Brazil; Acanthicus (2 sp.), Equatorial America; Loricaria (17 sp.), Tropical South America east of Andes; Acestra (4 sp.), Brazil and Guiana; Sisor (1 sp.), Northern Bengal; Erethistes (1 sp.), Assam; Pseudecheneis (1 sp.), Khasya Hills; Exostoma (2 sp.), Assam and Tenasserim; Bunocephalus (2 sp.), Guiana; Bunocephalichthys (1 sp.), Rio Branco, North Brazil; Aspredo (6 sp.), Guiana.

Sub-family 7 (SILURIDE OPISTHOPTERA) consists of two groups: Nematogenyina (2 genera), and Trichomycterina (3 genera), and is confined to South America. The distribution of is as follows:

the genera

Heptapterus (2 sp.), South America; Nematogenys (1 sp.), Chili; Trichomycterus (7 sp.), South America to 15,000 feet elevation; Eremophilus (1 sp.), Andes of Bogota; Pariodon (1 sp.), Amazon.

- Sub-family 8 (SILURIDE BRANCHICOLE) is confined to Tropical South America. It consists of one group, Stegophilina, and 2 genera: Stegophilus (1 sp.), Brazil; and Vandellia (2 sp.), Amazon Valley.

FAMILY 60. CHARACINIDE. (47 Genera, 230 Species.) "Fresh-water fishes, with scaly bodies and without barbels." DISTRIBUTION.-The Neotropical and Ethiopian regions.

This extensive family is divided by Dr. Günther into 10 groups, viz. Erythrinina (5 genera), South America; Curumatina