Bagrus.—Adipose fin long; a short dorsal with a pungent spine and nine or ten soft rays; anal fin short, with less than twenty rays. Barbels eight. The anterior and posterior nostrils are remote from each other, the posterior being provided with a barbel. Teeth on the palate in a continuous band. Eyes with a free orbital margin. Caudal forked; ventrals six-rayed.
This genus consists of two species only, common in the Nile, viz. the “Bayad,” B. bayad, and B. docmac. Both grow to a large size, exceeding a length of five feet, and are eaten. Chrysichthys and Clarotes are two other Siluroid genera from African rivers, closely allied to Bagrus. Similar Siluroids are common in the East Indies, and have been referred to the following genera: Macrones, Pseudobagrus, Liocassis, Bagroides, Bagrichthys, Rita, Acrochordonichthys, Akysis.
b. Amiurina.
Amiurus.—Adipose fin of moderate length; a short dorsal with a pungent spine and six soft rays; anal fin of moderate length. Barbels eight. The anterior and posterior nostrils are remote from each other, the posterior being provided with a barbel. Palate edentulous. Head covered with skin above. Ventrals eight-rayed.
The “Cat-fishes” of North America, of which about a dozen different species are known. One species occurs in China. Allied, but smaller forms are Hopladelus and Noturus, likewise from North America.
c. Pimelodina.
Platystoma.—Adipose fin of moderate length; a short dorsal fin with a pungent spine and six or seven soft rays; anal fin rather short. Snout very long, spatulate, with the upper jaw more or less projecting; the upper surface of the head not covered by the skin. Barbels six; the anterior and posterior nostrils remote from each other, none with a barbel. Palate toothed. Caudal forked; ventrals six-rayed, inserted behind the dorsal.
Twelve species from South America, some attaining a length of six feet, the majority being ornamented with deep-black spots or bands. Allied genera from South America, likewise distinguished by a long spatulate snout, are Sorubim, Hemisorubim, and Platystomatichthys, whilst Phractocephalus, Piramutana, Platynematichthys, Piratinga, Bagropsis, and Sciades, have a snout of ordinary length. The barbels of some are of extraordinary length, and not rarely dilated and band-like.
Pimelodus.—Adipose fin well developed; dorsal fin short, with a more or less pungent spine and six rays; anal fin short. Barbels six, cylindrical or slightly compressed, none of them belonging to either of the nostrils, which are remote from each other. Palate edentulous. Ventrals six-rayed, inserted behind the dorsal.
Of all South American genera this is represented by the greatest number of species, more than forty being well characterised; they differ chiefly with regard to the length of the adipose fin and barbels, and the strength of the dorsal spine. Singularly, two species (P. platychir and P. balayi), are found in West Africa. The majority are of but moderate size and plain coloration.—Allied South American genera (also without teeth on the palate), are Pirinampus, Conorhynchus, Notoglanis, Callophysus, Lophiosilurus.