98 ANNALS OF SCOTTISH NATURAL HISTORY 



show a peculiar subparallel wavy contortion for a good part of their 

 length. Nevertheless as usual they dichotomise twice, the dicho- 

 misations being fine and closely jointed, and the posterior margin 

 of the fin thin and delicate, and in those points the condition of the 

 fin essentially differs from that in the Docked Trout already de- 

 scribed. The anterior rays of the anal are not quite so long as 

 is usually the case. 



The second specimen (Plate IV. Fig. 2) is 12 inches in length, 

 and has a strikingly large head, the length of which from the point 

 of the snout to the posterior angle of the opercular flap is contained 

 only about 3f in the total. The caudal fin is oval, stiff, not expan- 

 sive ; the rays show a peculiar unparallel wavy contortion as in the 

 last specimen, but as the upper rays converge downwards and the 

 lower ones upwards a rounded contour is given resembling superfici- 

 ally that of the caudal fin of the docked fish from Loch-na-Maorachan 

 and Loch Enoch. But the condition here again differs by the fact 

 that the rays are finely dichotomised, while the posterior margin of 

 the fin, though reduced to being only half an inch in extent, remains 

 thin and delicate. 



It is only necessary to compare the figures on Plates IV. and V. 

 to perceive the difference, and to observe that the rays of the caudal 

 fins of the Carron specimens have a peculiar " frizzled up " appear- 

 ance not present in the others. 



Nevertheless it is interesting to find that in this malformed trout 

 (Fig. 2) from the Carron, the anal and pectoral fins are affected by 

 a condition resembling that in the Islay fish, while again the ventrals 

 and dorsal remain unaffected. In the anal the anterior rays are 

 stunted in growth, and deficient in dichotomisation, so that an 

 appearance is produced as if a large piece had been cut off from 

 the anterior part of the fin. 



Summary of Facts. 



1. Actual specimens are preserved, figured, and described, of 

 the Docked-tailed condition in trout (Sal mo fario, L.) from Loch-na- 

 Maorachan in Islay, Loch Enoch in Kirkcudbrightshire, and the 

 River Carron in Stirlingshire. 



2. There is credible testimony as to trout showing the same or 

 a similar malformation having occurred in the Gonar Burn, Lanark- 

 shire, near Wanlockhead, and in the Water of Leith, 1 but no 

 specimens have been preserved or described. 



1 The following passage occurs in Stoddart's " Art of Angling " 1836, p. 75. 

 " On the Water of Leith we saw a friend capture three successively out of one 

 stream during spring, all of which wanted the tail : this defect was probably 

 occasioned in winter, the water from which they were taken happening to be 

 extremely shallow, and the frosts shortly before somewhat severe." It is now of 

 course hardly possible to ascertain whether the defect in these fish was, or was 

 not, of a nature similar to the stunting of the fin-rays characteristic of the Docked 

 Trout of Islay. 



