328 Prof. M'lntosh's Notes on the Tunny. 



fins), which were tea dorsally (the first, however, being ap- 

 pended to the base of the second dorsal) and nine (slightlj 

 larger) ventrally, had their bases reddish brown, shading off 

 distally into bright yellow ; the free edge has a dark-fringed 

 margin | inch deep. The caudal had the upper half black, 

 with the frayed portions pinkish ; the lower half showed a 

 large amount of red or pink amongst the black portions, pro- 

 bably from injury. 



Tlie chief points in external configuration that fall under 

 notice are the scales and fins. The former, with the skin, 

 constitute a dense coat of mail (corselet) in front, and must 

 form a very efficient protection *. The fii'st dorsal fin again 

 is stated to have weak spines t ; but it is sufficient in this 

 specimen at least to point out that all are unbroken, while 

 the tough membrane between them is lacerated, and that 

 the powerful nature of the first spine is conspicuous. It is 

 slightly grooved posteriorly for the second spine, and the whole 

 fin can be folded into a hollow. There is likewise a flat- 

 tened depression for the pectorals, and this gives an indication 

 of the length of these organs when entire. 



The external form of the tunny has been represented by 

 various authors, and comparatively recently by Mr. Day, in 

 his excellent work on ' British Fishes ' %. The figures avail- 

 able for comparison, however, diff"er so much from the specimen 

 under consideration that a special sketch, aided by a photograph, 

 was made by Mr. Wilson, Demonstrator of Zoology, and will 

 be published in the ' Fourth Annual Report of the Fishery 

 Board for Scotland.' The premaxillary and maxillary region 

 is too long in the figures of Cuvier and Valenciennes §, as 

 as well as in Day's, in which the upper outline of the snout 

 is also too uniform ; and in these and in Yarrell's || and 

 Couch's H figures the eye is too large. The mandibular region 

 is too narrow and elongated in all the figures except Couch's 

 and the upper margin is too straight in profile. The shading 

 of the head in Day's figure gives a somewhat peculiar aspect 

 to the lateral view of this region, which seems to be too 

 long from the tip of the snout to the posterior margin of 

 the operculum ; and the same may be said of Cuvier and 



* The minute structure of these scales lias been investigated by Prof. 

 Quekett. 



t Vide, e. g., Giinther, Catalogue, ii. p. 362 ; Day, Brit. Fishes, p. 93. 



\ 'British Fishes/ ii. pi. xxxv. (1881). The earlier figures of Ron- 

 delet, Belou, Salvien, Gesner, Duhamel, Bloch, and Pennant have been 

 criticized by Cuvier and Valenciennes. 



§ Hist. Nat. des Poissons {Paris, 1831), viii. pi. ccx. 



II Brit. Fishes, 3rd tdit. ii. p. 20U. 



^ * Fishes of the British Islands/ ii. pi. Ixxxii. 



