MR. F. DAT ON THE LOCH-LEVEN TROUT. 



75 



exist between S. ccscifer (as he termed this form) and S.fario 

 are very striking. The pectorals of ccecifer, when expanded, 

 are pointed ; in S. fario they are rounded. The caudal fin in 



ccBcifer is lunated at the end; in 8. fario it is sinuous or 

 even. B. ccdcifer has never any red s2)ots ; 8. fario is scarcely 

 ever without them. The caudal rays are much longer in 8. ccb- 

 cifer than iu S. fario, in fish of equal length. In S. ccecifer the 

 tail-fin is pointed at the upper and lower extremities ; in 8. fario 

 they are rounded. The flesh of S. ccecifer is of a deep red, that 



S. fario is pinkish or often white. The cajcal appendages in 

 S. ccecifer are from 60 to 80 in number ; in S. fario I have never 

 found them to exceed 46." He also observed that this fish does 

 not appear to be peculiar to Loch Leven, as he had seen speci- 

 mens that had been taken in some of the lakes of the county of 

 Sutherland. 



Sir John Eichardson, in the ' Fauna Boreali-Americana,' I. c, 

 remarked that in " external form, the proportional size of various 

 parts of the head and gill-covers, the size of the scales and the 



dentition, agrees with S. lemanus Three individuals of 



the Loch-Leven trout that were dissected had each 73 pyloric 

 C9eca, and in one of them 59 vertebrae were counted." Yarrell 

 added nothing to the previous descriptions. Knox, ' Lone Glens 

 of Scotland,' 1854, observed of this trout of Loch Leven, that it 

 "is a beautiful silvery dark-spotted trout, imagined by some to 

 be peculiar to the lake. This, however, is not likely, since trout 

 quite resembling those of Leven are found in many northern 

 lakes " (p. 36). He concluded, after citing some of the opinions 

 of others, that he was " disposed to think that two species of 

 trout inhabit Loch Leven, independent of the common river 

 trout ; namely, the trout which lives on entomostracae, and comes 

 into season in December, January, and February ; and the trout, 

 which, feeding on the buccinum, and on flies, worms, aud all the 

 common food of the common river trout, comes into season later 

 in the spring" (p. 37). Li the 'Proceedings of the Linnean 

 Society' (Dec. 19th, 1854), Dr. Knox remarked that at first he 

 thought this a specific form, " although anatomical investigation 

 has not hitherto confirmed it." 



Dr. Giinther, I. gave a fuller description than the previous 

 authors whom I have quoted. He observed of this fish that it 

 has the " body much less stout than in S. fario .... In the 

 male sex a mandibular hook has never been observed. Maxillary 



