SILURUS GLANIS. 91 



The genus Silurus ranges from Europe, eastward through Afghanistan to 

 Cochin China, China, and Japan. 



It has no adipose fin, and the single dorsal fin, which includes more than 

 eight rays, has no sharp spine. There is a barhel to each maxillary bone 

 and to each mandible. The eye is lateral and above the angle of the mouth. 

 Five or six species are known, but the European Silurus glanis is the type 

 of the whole family. 



Silurus glanis ( 



D. 1/4, A. 90, V. 1213, P. 1/17, C. 17. 



The head is nearly as broad as long (Fig. 31). It has a long barbel on 

 each side of the upper jaw, and four short barbels on the lower jaw. The head 

 is somewhat compressed, flatly arched, rounded in front, and is nearly 



Fig. 31. SILURUS GLANIS (LINNAEUS). 



one-sixth longer than wide. Its height is two-thirds of its width, and its 

 length is about one-sixth of the length of the fish. 



The mouth is wide, with bow-shaped jaws, margined by thick, fleshy lips 

 which cover the teeth. The barbels of the upper jaw reach back at least as far 

 as the point of the pectoral fin, and behind the barbels the skin is folded so as 

 to form a deep furrow parallel to the edge of the lower jaw. The eyes are 

 very small, with a yellow iris, and a small pupil, which is elongated vertically. 

 Between the eyes are the apertures of the small posterior nasal openings, but 

 the anterior nasal apertures are prolonged forward as a tube, and placed near to 

 the margin of the upper lip. The mandible is somewhat longer than the upper 

 jaw. The teeth are compressed and conical, with their points recurved. The 

 teeth in the lower jaw form a band of four or five rows, divided into lateral 

 portions by the symphysis. On the pre-maxillary bone the teeth form two 



