OF THE BRITISH ISLANDS. 119 



slender tail developed in the form of a cord or whip to as 

 much as two or three times the length of the body ; 

 specimens measuring no less than fifteen feet across their 

 extended fins, with a weight of three hundred pounds and 

 upwards, have not unfrequently been recorded. The cast of 

 a small example of this species is included in the Buckland 

 Collection. The last, but by no means the least formidable 

 in point of size among the group now under discussion, is 

 the huge Ox Ray or Horned Ray (Dicerobatis giornce), No. 

 227, so called on account of the two horn-like processes 

 of the integument that are developed in front of the head. 

 Although small examples measuring but a few feet in 

 breadth have been driven as wanderers to our shores, in 

 the tropical seas which are its native home it attains to the 

 enormous proportions of ten or twelve hundredweight, with 

 a breadth across its expanded fins of twenty or thirty feet. 

 Upon the Italian coasts, where it is known by the title of 

 the Vacca, or Cow, and also that of the Manta-fish and 

 Devil-fish, it is held in great dread by the divers for sponges 

 and coral, whom the fish is said to attack, hovering over 

 and debarring their efforts to regain the surface, and after- 

 wards probably devouring them, the gape of the larger 

 examples, as in certain Sharks, being sufficiently wide as to 

 easily admit of the passage of a human being. 



ORDER IV. — Lamprey Tribe (Marsipobmnckii). 



Skeleton entirely cartilaginous, spinal column consisting 

 of a thick persistent notochord enveloped in a sheath but 

 devoid of vertebral centra ; no real jaws, the mouth circular 

 suctorial, armed with horny teeth, and frequently strengthened 



