OF THE BRITISH ISLANDS. 189 



The Basking-Shark, or Sun-fish, as it is sometimes incor- 

 rectly termed (Selache maximus\ is the largest of our British 

 fish, not unfrequently exceeding a length of thirty feet. It 

 makes a regular migration along the west coast of Ireland 

 and western isles of Scotland during the spring months of 

 the year, and on account of the value and quantity of the 

 oil obtainable from its liver is the object in such localities 

 of an important fishery. Although of such enormous bulk, 

 it is a very quiet and inoffensive species, armed with teeth 

 scarcely larger than those of an ordinary Dog-fish. A fine 

 preserved example of this species has been recently added 

 to the collection now in course of transfer from the British 

 to the adjacent New Natural History Museum. The fish 

 takes its names as above given from its habit of basking in 

 the sun at the surface of the water, and under which condi- 

 tions it falls an easy prey to the harpooners. The Six- 

 gilled Shark (Notidanus grisens), No. 205 ; the Centrina 

 (Centrinasabriani), No. 209 ; the Black Shark (Spinax niger) 

 No. 210 ; the Greenland Shark (Lcemargits borealis], No. 212 ; 

 and the Spinous Shark (Echinorhinus spinosus\ No. 213, 

 are among the larger forms that are but rarely taken in 

 British waters ; the cast of a fine example of the last-named 

 species, between seven and eight feet long, will be found 

 in the Buckland Museum. The remaining British Sharks, 

 including the Lesser Spotted Dog-fish, or Rough Hound 

 (Scyllium canicula), No. 206; the Larger Spotted Dog- 

 fish, or Nurse Hound (S. stellaris), No. 207; and the 

 Black-mouthed Dog-fish (Pristiurus melanostomus), No. 208, 

 are all of relative small size, not exceeding from three to 

 four or five feet in length, accustomed to prey upon Crus- 

 tacea and other animals inhabiting the bottom of the ocean, 

 and are for this reason known as " Ground Sharks." The 

 two first-named species, which are beautifully spotted with 



