360 SPINY-FINNED GROUP. 



Guinea, a sword of one of these fishes was found to have gone through the 

 sheathing one inch, next through a three-inch plank, and beyond that four and a 

 half inches into the firm timber ; and it was the opinion of the mechanics that it 

 would require nine strokes of a twenty-five-pound hammer to drive a bolt of 

 similar size and form to the same depth into the same hull ; yet this was accom- 

 plished by a single thrust of the fish." In the Mediterranean countries, where 

 these fishes are commonly taken in tunny-nets, their flesh is exposed for sale in 

 the markets. Geologically, the sword-fishes appear to be a comparatively modern 

 group, the earliest known representatives, which have been assigned to the existing 

 genus Histiophorus, occurring in the London Clay. 



The Scabbard-Fishes and Hair-Tails, — Family Trichiubid^. 



Another group of equal rank with the perch-like section is formed by a 

 family of fishes, characterised by the elongate and compressed or even band-like 

 form of the body ; the mouth having a wide cleft, and several large conical teeth 

 either in the jaws or on the palate. The dorsal and anal rays are long and many- 

 rayed, with the spinous nearly equal in length to the soft portion, finlets some- 

 times occurring behind the latter ; the pelvic fins, if present, are thoracic in position ; 

 and the caudal is sometimes wanting, but, when developed, forked. In all cases 

 the scales are either rudimental or wanting, but the air-bladder is constant. These 

 fishes are distributed over all tropical and subtropical seas ; but while some are 

 surface-forms, never found at any great distance from the coasts, others descend 

 to considerable depths in the open sea ; all are carnivorous, and many very 

 powerful. In India, writes Day, " these fishes are held in various estimation in 

 different places. In Baluchistan, and where salt is cheap, no one will touch them ; 

 but along the coasts of India they are more esteemed, mostly because being thin 

 or ribbon-shaped they can be dried without salting. In a fossil state these fishes 

 date from the lower Eocene of Switzerland and other parts of Europe, where they 

 are represented by extinct genera ; species of scabbard-fish occur in the Sicilian 

 Miocene, which has also yielded forms allied to the hair-tails (Trichiurichthys), 

 but with the body scaled. 



Among the better-known forms, the scabbard-fish {Lepidopus 

 caudatus) represents a genus characterised by the absence or rudi- 

 mentary condition of the pelvic fins, the long single dorsal, and the distinct 

 but small tail-fin. Although it may attain a length of 5 or 6 feet, the attenuation 

 of the body is so great that the whole weight does not exceed as many 

 pounds. The fish has a very wide geographical distribution, ranging from the 

 Mediterranean and warmer regions of the Atlantic to the Cape, and thence to 

 New Zealand and Tasmania, while it occasionally wanders to the British coasts. 

 This wide range may probably be taken as an indication that the scabbard-fish 

 is a comparatively deep-sea form. In New Zealand, where it is known as the 

 frost-fish, the scabbard-fish is highly esteemed for its flesh, which is white, rich, 

 firm, and tender, with an excellent flavour. On this account, says an anonymous 

 writer, " the fish is eagerly sought after, and commands a high price, as the supply 

 is irregular, and not equal to the demand. Not much is yet known of the manners 



