in the Fish Gallery of the Indian Museum. 49 



In most of the species the dorsal fin is greatly elevated 

 and is said to be capable of acting as a sail. 



They are the largest of all Acanthopterygians, and 

 they occur in the Atlantic, the Mediterranean, the 

 Indian Ocean, and the Pacific. 



They must not be confused with the " Saw-fishes " 

 which belong to the same Order with the Sharks. 



Family XIV. Trichluridce [Case 50]. 



A small family of highly rapacious marine fishes, 

 known as "Hairtails" and "Scabbard-fishes." The 

 body is low, compressed, and extremely elongate, and 

 the tail sometimes ends in a long filament. Scales are 

 absent or rudimentary. The dorsal and anal fins 

 consist of a very large number of rays. 



Two genera— Trichiurus, with three species, and 

 Thyrsites, with one species-are represented in Indian 

 Seas Trichiurus occurs in the West Indies and Atlantic 

 and in Eastern Seas from India to Japan. Thyrsites 

 occurs in the West Indies and North and South Atlantic, 

 in the Mediterranean, and in the Indian and Western 

 Pacific regions: the Indian species comes from the 

 depths. 



Family XV. Acronuridce [Case 50]. 



The « Surgeon-fishes " are a small family, the members 

 of which occur in shoals among coral-reefs. They are 

 recognized (1) by their rough leathery skin, (2) by the 

 presence of sharp-edged plates or spines on the sides of 

 the tail and (3) by their incisor teeth, which are adapted 

 for browsing on coral. The plates on the tail are 

 capable of inflicting severe injury, and I have seen a 

 man's palm slashed right across, down to the blood- 

 vessels, by the tail of one of these fishes. 

 7 



