BRAMOIDS. 



81 



certainly apply here, too. Only the more elongated (lower) form of the 

 body might perhaps suggest a difference of species. But in a genus 

 whifli in this respect is as variable as Brama, we can scarcely draw 

 a diiforence of species from the higher or lower form of the body 

 when the difference is so small and measured in only one single spe- 

 cimen. Nor can I find any other ri-ason fur distinguishing Johnson's 

 Brama princepx from this species than the fact that in the large spe- 

 cimens from Madeira (68() — 838 mm. long, excluding the lobes of the 

 caudal fin) examined by Johnson, there was "a broad keel on each side 

 of the middle portion of tlie tail". This discovery is especially im- 

 portant as it clearly refers these forms to the group of the Scombro- 

 morph fumilie.'i, Vmt it does not therefore preclude the possibility of 

 Ihis being a chariiclcr of age wliich has not yet appeared in the spe- 

 cimens described under the names of Br. lonfjipinnis and Bv. Raschii, 

 the largest of which, Lowe's specimen, is 4G3 mm. long. Thus in 

 Scandinavia as well as in the Atlantic off Madeira, we should have 

 to distinguish two species, which are called by the fishermen of Ma- 

 deira "Frcira" {Br. Rail) and "Freira do alto" (/>'/•. longijnnnis). 

 From the changes due to age in the relative length of the dorsal 

 and anal fins, which are given below, it seems quite possible that the 

 j-oung specimen figured by Lowe in fig. 2, plate IV of his much-quoted 

 work belonged to this species, though to judge by the figure this circum- 

 stance, had it occurred in a more fullgrown specimen, would certainly 

 have referred it to the West Indian branch of the genus. 



Rasch's Sea-Bream is evidently an intermediate 

 form between Brama Rail and the West Indian branch 



of \\\v genus, the latter being distinguished by the 

 shortest uu.mI hii, but, however, including a high-finned 

 form {Br. Brevorti) as well as two comparatively low- 

 finned (Br. Af/assim and Br. Saussurii)", between which 

 we should have to distinguish if the distinction of spe- 

 cies in this branch of the genus could be regarded as 

 fixed. The relation between Rasch's and Ray's Sea- 

 Breams is in most respects, howe\'er, a distinct ex- 

 pression of the ditt'erent stages in one and the same 

 course of develoi)ment, in Avliich the former represents 

 the less ad\anced stages. Tins appears even in the 

 more perfect retention of the spines on the scales, but 

 also strikes us in several of the other changes due to 

 age, which we have traced as far as the scanty mate- 

 rials at our dispo.sition and the measurements given by 

 other writers admit. It is with titis object that we have 

 drawn up tlie following table of comparison, assuming 

 that Brama princeps represents one of the most highly 

 developed stages of Br. lonfjipinnis. 



Lenstb of the bodv to the end of the middle 



iidal ravs mm. 



1) Length of the anal tin 



2) „ „ ,, lower jnw 



3) Greatest height of the dorsal fin 



4) „ „ „ 



5) Length of the aual tin 



in % of that of the body 



„ „ ,, „ „ ,, anal tin _ 



„ ,, ,, its length 



„ „ ,, the length of the head .._ 

 „ „ „ „ „ „ „ dorsal. 



6) „ „ „ head 



7) „ „ „ „ 



8) » „ „ „ 



10) „ „ „ lower jjuv 



11) „ „ „ „ „ 



12) , .. 



13) Breadth of the interorI)it;il space ,, „ „ 



14) Lenarth ,, ,, dorsal tin 



j» »» » 





lo) 



16) 

 17) 

 18) 



pectoral tins 

 ventral ,, 



» ,' ,, ,» 



„ body 



,, dorsal fin 



„ anal „ ..... 



„ pectoral fins. 



,, body 



,, head 



,, dorsal fin 



„ lower jaw 



„ bodv 



„ ,, „ „ „ „ ,, pectoral fins... 



!i 1! »i ,) „ „ „ body 



„ „ „ „ greatest height of the dorsal. 



,, I- 



In all these proportions except Nos. 4, 5 and 18 we 

 can easily see that where the changes of age in Br. 

 Rail shoNv an increasing ratio, in Brama longiplnnis the 

 percentage is least, and vice versa. We must, however, 

 pay attention to the age as well, provided it be expressed 

 by the length of the body, for then the specimens de- 



scribed by Johnson nmst have passed through changes 

 considerably greater than the oldest specimen of Br. 

 Rail. It is from this cause, too, that, in the thi'ee ex- 

 ceptional relations (4, 5 and 18), we should really look 

 for the ratio of Esmark's specimen nearest to, but still 

 below or above that of the older specimen of Br. Rail. 



" With respect to these forms see Lunel, 1. c, pp. 182 etc., Plate II. 

 Scandinavian Fishes. 



11 



