48 A Guide to the Zoological Collections 



from great estuaries, which at certain seasons it ascends, 

 even into freshwater limits. The eye is small and the 

 fish probably relies more on its tactile filaments than 

 upon its sense of sight. The use of the "Topsi" as 

 food is well known : equally estimable is the Silli fish, 

 which is also valuable for its isinglass. 



Polynemus occurs in the West Indies, in the seas of 

 India, and in the tropical seas of the Western Pacific. 



Family XII. Scicenidce [Cases 51-52]. 



In this family, the members of which share the 

 habitat of the " Topsi," there is a short spinous dorsal 

 fin and a very long soft dorsal fin. 



It is a large family and is represented in Indian seas 

 by four genera — Sciccna y Scicenoides, Umbrina, and 

 Otolithus, all of which are very good to eat, besides being 

 capable of furnishing isinglass. All four genera range 

 from the Gulf of Mexico and neighbouring coasts of 

 America to the Atlantic and Mediterranean and east- 

 wards to the Indo-Pacific. 



The Indian species are very common at the mouths of 

 the estuaries of big rivers, and several of them are able 

 to make a croaking sound : none of them appear to be 

 confined to freshwater, though several enter freshwater 

 freely. 



Family XIII. XipliMdce [Case 51]. 



The " Sword-fishes " are characterized by having the 

 bones of the upper jaw prolonged to form a long 

 sword or lance of great sharpness and strength, and a 

 very formidable weapon of offence. By means of it 

 they are able to attack whales successfully ; and in the 

 Indian Museum there is a piece of ship's timber that has 

 been perforated by a sword-fish. 



