THE CATFISHES OR SHEATHFISHES 2827 



Clarias anguillaris is a well-known representative of the first sub- 

 E el-Like 



' family, in which the long dorsal and anal fins extend nearly through- 



out the length of the trunk. It belongs to a minor group confined to 

 Africa and the Oriental region, and characterized by the dorsal fin being either com- 

 posed of weak rays throughout its length, or with its hinder portion modified into a 

 fatty fin. 



The wels (Silurus giants}, shown in the larger figure of the illus- 

 tration on p. 2808, is the typical representative of the second sub- 

 family, in which the rayed dorsal fin is but little developed, and if present at all 

 occupies only the hinder region of the trunk; the fatty portion being small or want- 

 ing. The anal fin is not much shorter than the caudal region of the backbone, and 

 the pelvic fins are behind or below the dorsal. In the wels and its congeners the 

 short dorsal has no pungent spine; the fatty fin is wanting; there are two upper and 

 two or four lower barbels; the head and body are naked; and the tail fin is rounded. 

 The wels itself, which is confined to the European rivers eastward of the Rhine, has 

 six barbels, of which the upper pair are considerably longer than the head, and com- 

 monly attains a length of from six to nine feet, although it occasionally grows to 

 thirteen feet. In color the head, back, and edges of the fins are bluish black, the 

 sides greenish black spotted with olive green, and the under parts reddish or yellow- 

 ish white with blackish marblings. Frequenting rivers and lakes with muddy 

 bottoms, the wels feed on fishes, frogs, and crustaceans, but will also seize and 

 pull down ducks, geese, or other birds swimming on the surface. The spawning 

 time is in the middle of summer, when these fish resort to the shallows in order to 

 deposit their eggs on the stems and leaves of water plants. 



Another gigantic species is Yarrell's catfish (Bagarius yarrelli) 



from the large rivers and estuaries of India and Java, which attains a 

 fish, etc 



length of fully six feet, and from its huge head and mouth is one of 

 the ugliest fishes in existence. The only member of its genus, it belongs to a 

 subfamily in which the rayed dorsal fin is short, and situated in the hinder part 

 of the body in advance of the pelvics; and there is always a fatty fin, which 

 may, however, be short; and the anal is shorter than the caudal region of the 

 backbone. When nasal barbels are developed, they belong to the hinder nos- 

 trils. In the group of genera to which Yarrell's catfish belongs the front and 

 hinder nostrils are placed near together, with a barbel between them; and in 

 this particular form there are eight barbels, and the upper surface of the head 

 is naked. This gigantic species is of especial interest on account of its fossil- 

 ized remains occurring in the Pliocene deposits of the Siwalik hills in North- 

 eastern India. 



The well-known genus Arius from all the tropical regions of the world, be- 

 longs to another group of the same subfamily, in which the front and hinder 

 nostrils are close together, but have no barbels, although the hinder pair are pro- 

 vided with a valve. The tropical American genus Pimelodus is the typical repre- 

 sentative of a third group of the same subfamily, in which the two pairs of nostrils 

 are equally devoid of barbels, but are placed at a considerable distance apart. The 

 largest species is the leopard catfish or suravi (P. pati} from the rivers of 



