FISHES. 125 



193. Scombresox saurus {Walb.). Saury. Skipper. 



Occasionally taken in harbours and shallow water. Reported 

 from Scarborough only. 



194. Exoccetus evolans Z. Flying-fish. 



195. Exocoetus volitans Z. Greater Flying-fish. 



Fam. ESOCID-ffi. 



196. Esox lucius L. Pike. 



Freshwater resident, abundant in the ' deeps ' of the middle 

 and lower reaches of all the rivers except the polluted ones ; 

 also in ponds, canals, and reservoirs, into which it has been 

 introduced. 



Fam. STERNOPTYCHIDJE. 



197. Maurolicus borealis {Niiss.). Argentine. Pearlside. 



Of rare occurrence at Redcar, where it has been found from 

 January to May. Mr. T. S. Rudd first met with it there 

 in May, 1841; in T843, he took thirteen specimens j in 

 Feb., 1851, four; and in February and March, 1852, forty. 

 Elsewhere in the British Isles it appears only to have 

 occurred singly. The species is represented in the British 

 Museum by Yorkshire specimens sent by Mr. Rudd. 



Fam. SALMONIDJE. 



198. Salnno salar Z. Salmon. 



Freshwater resident, periodically descending to the sea, 

 abounding in all the Yorkshire rivers except the Aire, from 

 which it is excluded by pollution, and the Hull, Don, 

 Wiske, and Codbeck, which are too sluggish. Into the 

 Esk it was introduced some twelve years ago. The 

 spawning season in the Yorkshire rivers is in November 

 and December, immediately after which, in January and 

 February, the kelts or spent-fish descend to the sea. The 

 date of their return, as fresh-run fish, varies greatly, and is 

 dependent upon the state of the rivers — if either July, 



