SALMONID^E. 101 



varies. Fins — the pectoral is as long as the head excluding the snout, it is not 

 quite so pointed as in the Loch Leven form, nor so rounded as in the common 

 brook-trout, but intermediate between the two. Scales — 125 rows along the 

 lateral-line, 15 from the base of the adipose dorsal to the lateral-line, 25 from the 

 lateral- line to the base of the ventral fin. Coscal appendages 46 in the one 

 examined. Length of head 4 §• to 5 in the total length. Colours — silvery, with 

 the upper two thirds of the body and head closely covered with x-shaped or round 

 black spots, and in two of the examples a few red spots but mostly confined 

 to the lateral-line. The loch has a pure white sandy bottom, which probably 

 accounts for their silvery colour. When fresh caught their backs are of a vivid 

 green, varying to pale sea-green and dark olive, in accordance with the depth of 

 the water in which they live. Dorsal fin covered with black spots. 



These fish have the silvery appeaiunce of anadromous forms, and externally 

 strongly resemble the Loch Leven variety, but the number of ccecal appendages is 

 different, being almost identical with that observed in a Loch Leven example raised 

 at Howietown, and one step nearer removed from its marine ancestry than is the 

 true S. leveiiensis. Did this species run up rivers, doubtless they would take on 

 the colours of the brook-trout, as they have its dentition. They attain to 3 lb. or 

 4 lb. weight. 



Mr. J. Harvie-Brown (Land and Water) observes that at a far inland locality 

 in Sutherlandshire, brown trout, dark and spotted, were caught in 1877, and 

 introduced to a chain of lochs in the same county, which have their sources in 

 innumerable springs of clear water from granite and limestone mountains 

 (princi pally the former, as the limestone, for the most part, is at a lower level). 

 These fish became, in a single year, silvery and covered with minute bright scales 

 like sea-trout, and grew to the size of 1 lb. weight in twelve months, from at most 

 \ of a lb. The food in the loch is shell-fish and. tadpoles, and the bottom granite, 

 gravel, and sand. 



Monstrosities. — Hog-backed trout of Plinlimmon, Cambridge Quart. Mag. 1833, 

 p. 391 ; Cobbold, Edinb. New Phil. Journ. ii, 1855, pi. vi. 



1 1 3-1 2 5 



B. xii, D. 12-15 (£ft) | 0, P. 13-15, V. 9, A. 10-12 ( T ! T ), C. 19, LI. 



Vert. 57-60. 



Length of head 4j to 4| (in old breeding males 3|), of caudal fin 7 to 1\ 

 height of body 4|- to 5 in the total length. Head much more pointed in some 

 forms than in others. Eyes — diameter 4| to 6 in the length of the head, varying 

 with the size and age of the specimen, lj to 2 diameters from the end of the snout 

 and the same apart. In old breeding males the eyes are comparatively smaller, 

 and as much as 3 or 3^ diameters from the end of the snout and also apart. 

 Teeth — in a double zigzag row along the body of the vomer, and in a transverse row 

 across the anterior portion of that bone where it is joined with the palatine arch. 

 Fins — the first dorsal (except in old breeding males), as a rule, commences some- 

 what nearer to the snout than to the base of the upper caudal ray ; the height of 

 the anterior ray usually exceeds the length of its base. Origin of adipose dorsal 

 fin about midway between the anterior insertion of the base of the rayed dorsal 

 and the posterior extremity of the upper caudal lobe. Pectoral as long as the 

 postorbital portion of the head, or even of the entire head excluding the snout, in 

 some examples it is more pointed than it is in others. Ventral inserted beneath the 

 middle or last third of the base of the dorsal fin. Caudal forked in the very 

 young, cmarginate in those of a medium size, becoming square in large examples, 

 or even rounded. Scales — from 13 to 15 rows between the hind end of the 

 adipose dorsal fin in a row passing downwards and towards the lateral-line. 

 About 26 or 27 rows from the lateral-line to the base of the ventral fin. Ca>cal 

 appendages — these differ considerably, apparently being influenced to a great 

 extent by the locality they inhabit and the food which they can obtain. 

 Colours — these vary as has already been observed (see page 57), not only with 

 locality but also owing to changes of food. Those from Wales and along the 

 S.W. coast are of a somewhat darker appearance than those from the Midland 

 counties and towards the north, and have rather more black but less red spots. 



