] . SALMO. 



35 



B. 10-11. 

 L. transv. 



A. 11-12. P. 16. V. 9. L. lat. 120-125. 

 Vert. 59, Caec. pylor. 39-47, rarely more. 



D. 14. 



27 



38-40" 



Attaining to a length of about 3 feet ; female mature at a length 

 of fi'om 12 to 13 inches. 



Head rather long, compared with its depth ; operculum rather 

 short, its length being contained in its depth once and four-fifths in 

 large (32-in.) specimens, once and three-lifths in adult ones (22-in.), 

 once and tvro-lifths in specimens in the Grilse-state, and once and 

 one-fifth in specimens in the Parr-state ; like the other bones of the 

 skuU, it is well ossified, and striae radiating from the base towards 

 the hinder edge are much more 

 conspicuous than concentric mar- 

 ginal striae. The hind margin of 

 the giU-cover is more or less pro- 

 duced, the suboperculum projecting 

 beyond the end of the opercle. 

 The posterior point of junction of 

 operculum and suboperculum is 

 much nearer to the lower end of the 

 suboperculum than to the upper 

 end of the gill- opening; and only 

 in very young examples are the dis- 

 tances between these points equal. 

 Praeoperculum with a distinct lower 

 limb, Avith the angle rounded, and 

 with the hind margin convex or undulated, snbvertical. Snout 

 rather long, much produced in males, in which the lower jaw be- 

 comes hooked during the spawning-season. Maxillary strong, solid, 

 longer than the snout ; in specimens of the Grilse-state (about 12 in. 

 long) it already extends to the vertical from the hind margin of the 

 orbit, or even beyond it ; and in larger ones, females as well as 

 males, it constantly exceeds that line ; in examples 6 inches long 

 it reaches beyond the middle of the orbit. Head of the vomer tri- 

 angidar, broader than long, toothless in adult examples, and armed 

 with a few teeth across its hinder margin in young ones ; body of 

 the bone with a sharp longitudinal ridge, in the sides of which the 

 teeth are inserted, forming a single series, and alternately pointing 

 towards the right and left; in pure (non-hybrid) specimens these 

 teeth are lost in the Grilse-state, so that only the two or three 

 anterior remain in specimens more than 12 or 13 inches long. 



Fins of moderate length : the caudal fin is forked in specimens 

 6 inches long, in which the longest rays are not twice as long as the 

 middle ones ; it shows only a slight emargination in specimens in 

 the Grilse-state, and is perfectly truncate in adult examples, but 

 never rounded. Tail not elongate, covered with thin, short, rounded 

 scales, hke the body ; there are fourteen scales in a transverse series 

 running from behind the adipose fin obliquely forwards to the lateral 

 line. Scales of young examples very deciduous. 



This species loses the Parr-marks as soon as it is from 5 to 6 inches 



1)2 



