98 SWORD-FISH. PILOT-FISH. RIBBON FISH. SURGEON.^ 



29. The Tribe of Sword-fishes, is distinguished from all 



p. ,g other fishes of the same family, by 

 the beak, or long sword-like point, 

 which terminates the upper jaw, 

 (Fig. 49.) and forms a powerful 

 weapon with which these fishes 

 SWORB-FISH. attack the largest marine animals. 



30. The Sword-fishes properly so called, Xiphias, are 

 without ventral fins, and the prolongation of the muzzle is 

 flattened horizontally, and is cutting like a broad sword blade. 

 But one species is known, Xiphias gladius, which is often 

 fifteen or even more feet in length ; it is more common in the 

 Mediterranean than in the Atlantic. The flesh, which is white 

 and compact, is delicate. This fish is not uncommon near our 

 own coasts, and is often taken with the harpoon. 



< 31. Another tribe, called Centronotus, is characterised by the 

 absence of the membrane that unites the rays of the first dorsal 

 fin, which consequently remain free. Among other fishes be- 

 longing to this tribe is the Pilot-fish, (Naucrates, or Scomber 

 duct or,} so called from its habit of following vessels, to seize 

 what may be thrown overboard, and also from the habit attributed 

 to it, of conducting the Shark, which, directed by the same instinct, 

 also very frequently accompanies vessels at sea with great perse- 

 verance. They have a fusiform body, very small scales, nearly 

 the same as the mackerel, and cartilaginous carinae on the sides 

 of the tail like the Tunny. The common species is about a foot 

 long. 



32. The FAMILY OF T^ENIOIDES is composed of Acanthoptery- 

 gians, which approximate the Scomberoides ; they also have 

 very small scales, but are distinguished by an extremely elongated 

 body, very much flattened on the sides, the form of which has 

 obtained for them the name of RIBBON-FISHES. 



33. The FAMILY OF THEUTYES also resembles the Scomberoides. 

 It is composed of a small number of fishes, the body of which is 

 compressed and oblong, with a small mouth, but slightly, if at 

 all protractile, and armed in each jaw, with a single row of 

 cutting teeth ; the palate and tongue are without teeth, and there 

 is but one dorsal tin. The Theutyes are herbivorous. The 

 ACANTHURI, called Surgeons, on account of a large, moveable 



29. How is the tribe of Sword-fishes distinguished? 



30. What are the characters of the Sword-fish properly so called ? 



31. What is the Pilot Fish? 



32. How are the Tsenioides distinguished ? 



33. What are the characters of the family of Theutyes? What are the 

 Acanthuri ? 



