52Q Prof. M'lntosh's Notes from the 



market recalls a similar case included in tlie Tenth Annual 

 lleport o£ the E'ishery Board for Scotland (1892) *. In this 

 the right (coloured) side presents a fairly normal appearance, 

 except that near the caudal an irregularity of the fin-rays — 

 both dorsal and anal — occurs. A few irregular fin-rays are 

 at a different level from the rest when the fish is placed on a 

 flat surface right side up. On the left side the lateral line 

 posteriorly is curved gently to the dorsal edge, and terminates 

 about half an inch in front of a somewhat elevated border 

 stretching between the dorsal and anal interspinous regions. 

 This elevated border is fringed with a continuous series of 

 rays. The first of the irregular series ventrally pass from 

 the anal interspinous bones at a forward angle, and the trans- 

 verse rays follow in order. The rays joining the dorsal are 

 crowded and almost form a double series at the prominent 

 fold of the region. The interspinous elements show a 

 tendency both at the dorsal and the ventral edge to follow 

 the abnormal transverse or vertical fin, but they appear to be 

 deficient in the central region, though slight folds are visible. 

 The lateral line commences anew from beneath the centre of 

 the transverse or vertical fold, and goes straight back, as 

 usual, to the caudal. The left side is of the normal colour, 

 with the exception of a circular patch of black about \ of an 

 inch in diameter, which is situated below the lateral line and 

 almost covered by the membrane and rays of the abnormal 

 fin. Above the lateral line is another minute speck. The 

 scales of the caudal region on the right do not appear to 

 differ from an ordinary example, and those on the lett do not 

 call for remark. 



Mr. Boulenger's specimen agrees with the foregoing in the 

 absence of the fin-frill from the coloured side and in the 

 presence of a deep notch dorsally and ventrally behind the 

 abnormal fin. There are slight differences in regard to the 

 continuity of the marginal fins and the abnormal one, but 

 the condition in each evidently springs from the same cause. 

 He thinks that at an early stage of its existence the fish lost 

 the posterior part of its caudal region at the point now 

 indicated by the truncature on the blind side ; " it at once 

 proceeded to repair the injury by producing a secondary 

 terminal fin, viz., the transverse structure connecting the 

 dorsal with the anal . . . But at the same time, or soon after, 

 the true tail asserted its rights, and grew again, alongside the 

 secondary fin, and this regeneration would fall under what 

 Prof. Giard has designated as ' Regenerations hypotypiques 



* Part iii. pp. 298 & 29;), pi. xvii, Hy. 5. 



) It 



