FISHES. 125 
193. Scombresox saurus (MWa/d.). Saury. Skipper. 
Occasionally taken in harbours and shallow water. Reported 
from Scarborough only. 
194. Exoccetus evolans Z. Flying-fish. 
195. Exoccetus volitans Z. Greater Flying-fish. 
Fam. ESOCIDZ. 
196. Esox lucius Z. 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. STERNOPTYCHIDA. 
197. Maurolicus borealis (JVss.). 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 1843, he took thirteen specimens; 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. SALMONIDZ. 
198. Salmo 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, 
