Sharks and Rays 



669 



fhulo by W. aamUe-Kent, F.Z.S.] 



SHOVEL-NOSED SKATE. 

 Known also as the Halavi Ray. 



[Alilford-on-Sea. 



its trivial name. All these 



rays, in fact, have some form 



or other of formidable offen- 

 sive and defensive apparatus. 



The STING-RAY has on its 



tail a fearful serrated dagger, 



6 or 8 inches long in large 



examples ; while the TORPEDO- 



or NUMB-FISH has electric 



organs in the head, with the 



aid of which it can give a 



shock sufficiently strong to 



paralyse the fishes on which 



it feeds. 



Two interesting peculi- 

 arities of the rays deserve 



notice in concluding this 



chapter. The first is that 



their egg-purses, instead of 



attaching themselves with 



ti laments to weeds and rocks, 



like those of the sharks, are 



provided with a sticky secretion which answers the same purpose of anchoring them in 



security from currents that would carry them out into deep, cold water. The second is 



the sexual difference in the teeth, which are pointed in the male and flat in the female. 



Whether this difference in the teeth (which may be likened to that between the bills of 



the male and female Huia-bird of New Zealand) indicates a corresponding difference in food, 



or, on the other hand, some co-operation between the sexes in procuring it, is an interesting 



question that our present slight knowledge of the habits of these fishes does not enable us 



to answer. 



Finally, attention must be drawn to the remarkable transformation which the breast-fins 



and tail have undergone. The 

 j 1 : 3$% f rmer have developed into 



powerful swimming-organs, 

 locomotion being effected by 

 their undulatory movements, 

 instead of by similar move- 

 ments of the whole body, or 

 by side-to-side motions of 

 the tail, as in other fishes. 

 Whilst the latter, no longer 

 used in swimming, has either 

 been reduced to a mere vestige, 

 as in the HORNED OX-RAY, 

 or has become developed into 

 a long and tapering " whip- 

 lash," provided with a poison- 

 spine. In such cases the long 

 tail is used to encircle prey, 

 and at the same time to force 

 the victim on to the deadly 



PAINTED SKATE. 



So called on account of its conspicuous coloration. 



Spine. 



