436 FISHES. 



as the preceding allied forms. It grows to a length of five or 

 six feet, but its body is so much compressed that it does not 

 weigh more than as many pounds. It is well known in 

 New Zealand, Avhere it is called " Frost-fish," and esteemed 

 as the most delicious fish of the colony. A still more 

 attenuated species (Z. tenuis) occurs in the sea off Japan, at a 

 depth of some 340 fathoms. 



Trichiurus. — Body band-like, tapering into a fine point, with- 

 out caudal fin. One single dorsal extending the whole length of 

 the back. Ventrals reduced to a pair of scales, or entirely 

 absent. Anal fin rudimentary, Avith numerous extremely short 

 spines, scarcely projecting beyond the skin. Long fangs in the 

 jaws ; teeth on the palatine bones, none on the vomer. 



The " Hairtails " belong to the tropical marine fauna, 

 and although generally found in the vicinity of land, they 

 wander frequently out to sea, perhaps merely because they 

 follow some ocean-currents. Therefore they are not rarely 

 found in the temperate zone, the common West Indian species 

 (T. lepturus), for instance, on the coast of England. They 

 attain to a length of about four feet. The number of tlieir 

 vertebrae is very large, as many as 160, and more. Six 

 species are known. 



Epinnula — Body rather elongate, covered with minute scales, 

 The first dorsal fin continuous, with spines of moderate strength, 

 and extending on to the second ; finlets none ; ventrals well 

 developed. Lateral lines two. Teeth of the jaws strong ; 

 palatine teeth, none. 



The "Domine" of the Havannah, U. magistralis. 



Thyrsites. — Body rather elongate, for the greater part naked. 

 The first dorsal continuous, with the spines of moderate strength, 

 and extending on to the second. From two to six finlets behind 

 the dorsal and anal. Several strong teeth in the jaws ; teeth 

 on the palatine bones. 



The species of this genus attain to a considerable size 

 (from four to five feet), and are valuable food fishes ; Th. aiun 



