SEA-BATS AND DORIES 



623 



young of the horse-mackerel seeking shelter beneath the " umbrella " of a jelly-fish till they 

 are big enough to defend themselves. 



But the most remarkable members of this family are the SEA-BATS. Few in species and 

 confined to the Red Sea, Indian Ocean, and Western Pacific, they are nevertheless in those 

 regions very common. Although not used as food-fishes, they are of extreme interest on account 

 of their shape, which is nearly oval and much compressed from side to side, and the form of 

 their fins, which in some species are excessively developed. Young sea-bats differ markedly 

 from the adults in the much greater length of the fin-rays, so much so that they have 

 frequently been described as distinct species. 



We pass now to the DORIES, which recall the Sea-bats in the oval and compressed form 

 of the body. The resemblance to sea-bats is, indeed, so close that the latter are frequently 

 described as dories. The mouth of the members of this family is so constructed that, 

 when opened, the upper jaw is thrust forward, and the whole mouth forms a kind of long tube. 

 Dories inhabit the seas of the temperate regions, two species being fairly common in British 

 waters. The best known of these two is perhaps the JOHN DORY, the largest specimens 

 of which attain to a weight 

 of 1 8 Ibs. Mr. Cunning- 

 ham has described the very 

 peculiar way in which the 

 dory captures its prey. " It 

 does not," he writes, " over- 

 take it by superior speed like 

 the mackerel, or lie in wait 

 for it like the angler, but 

 stalks it and approaches it 

 by stealth. It is able to do 



this in consequence of the 



extreme thinness of its body 



and the peculiar movement 



of its hinder dorsal and 



ventral fins. The dory places 



itself end on towards the fish 



it desires to devour, and in 



this position it is evident 



that it excites no alarm on 



the part of its prey. The 



appearance of the dory, seen 



in this way, is a mere line 



in the water, to which no 



particular significance can be 



attached. I have not par- 

 ticularly noticed the "effect 



of the ribbons of membrane 



which project from the dorsal 



fin. But I have observed 



that the movements of the 



dory are very gradual, except 



in turning; it alters the 



position of its body by a 



turn of the tail or side-fins, 



and then swims forward by 



vibrating the second dorsal 



fhttt by W. Savillt-Ktnt, F.Z.S.] 



LONG-FINNED DORY 



[Milftrd-m-St* 



