BEAKED RAYS. 



539 



jaws ; but the fish darts over its victim so as to cover and hold it down with its 

 body, when it is conveyed by some rapid motions to the mouth. Rays do not 

 descend to the same depth as sharks ; with one exception, none are known to have 

 been caught by a dredge working in more than one hundred fathoms. The majority 

 are coast-fishes, and have a comparatively limited geographical range, none extend- 

 ing from the northern into the southern temperate zone. Some of the eagle-rays 

 are, however, more or less pelagic, although when these are met with swimming in 

 the open sea it is probable that shoal-water exists at no great distance. As may 

 be observed in many of the lochs on the west coast of Scotland, where these loath- 

 some creatures may be seen flapping lazily alone at the bottom of the clear water, 

 skates and rays are more or less gregarious fishes. They frequently arrive suddenly 

 on oyster-beds, — to the dismay of the owners, — where they appear to remain so long 



halavi bay (1 nat. size). 



as any of the molluscs are obtainable. Writing of the species armed with caudal 

 spines, Day observes that they " lie concealed in the sand, and are reputed to be 

 able to suddenly encircle fish or other prey swimming above them with their long 

 whip-like tails, and then wound them with their serrated tail-spines." Many rays 

 ascend rivers to considerable distance, and some kinds, especially in Tropical 

 America, are exclusively inhabitants of fresh waters. Nearly all lay eggs. 



To illustrate the typical genus, which is represented by about 

 Typical Genus. & ^^ gpecies from the warmer seas , we take the halavi ray 



(Rhinobatis halavi), which ranges from the Mediterranean and the coasts of Western 

 Africa to China. In these fish the depressed body passes imperceptibly into the 

 tail ; the muzzle is produced into a long beak, the space between which and the 

 pectoral fin is occupied by a membrane ; and the wide nostrils are oblique, with 

 their front valves separate. The blunt teeth are marked by an indistinct trans- 



