442 FISHES OF THE FIRTH OF FORTH. 



the fishermen's nets, — the only way in which it is usually 

 caught, for it rarely swallows a bait. The manner in which 

 this fish defends itself, shews its consciousness of the formi- 

 dable weapon it carries on its tail. When seized or terrified, 

 its habit is to twist its long, slender, and flexible tail round 

 the object of attack, and, with the serrated spine, tear the 

 surface, lacerating it in a manner calculated to produce vio- 

 lent inflammation.'" It is said, that the ancients were in 

 the habit of using the spine of this species to tip their ar- 

 rows and spears. The flesh of the Sting Ray is seldom 

 eaten, as being rank and disagreeable to the taste ; when 

 cut, it emits a stronger ammoniacal odour than any of the 

 other species of the family. 



ORDER III.— CYCLOSTOMI. 



Branchia purse-shaped, fixed, opening outwards by se- 

 veral apertures ; jaws represented by an immoveable carti- 

 laginous ring, formed by the union of the palatine and 

 mandibular bones ; body elongated ; no pectorals or ven- 

 trals ; the skeleton very imperfectly developed ; the intes- 

 tinal canal straight and narrow, without a spiral valve. 



Genus PETROMYZON.— Seven branchial openings 

 on each side of the neck ; maxillary ring armed with strong 

 teeth. 



Petromyzon marixus.* — The Sea Lamprey. 



Specific Characters. — Body greenish, marbled with dark brown ; 

 second dorsal and caudal fins separate. 



Description. — From a specimen two and a half feet in length. 

 Body cylindric and nearly of equal size as far as the first dorsal fin, 

 from thence gradually tapering to the end of the tail ; head indis- 

 tinct ; from the point of the snout to the posterior part of the eye, 



* Petromyzon marinus, Cuv., Yarr., Jen., Penn., Flem. 



