6 PROFESSOR STRUTHERS. 



siderably less. In the 50-feet-long B. musculus the length was 4 

 feet 2 inches along the ulnar border, 6 feet along the radial border, 

 and after removal the measurement from the head of the 

 humerus was the 5 feet 11 inches given in the table. In this 

 Megaptera the measurements were: inferior border, 12 feet; 

 superior border, 10 feet 3 inches ; along the middle, straight, 

 11 feet 8 inches; from the head of the humerus, after removal 

 of the fin, 12 feet. The measurement at the shorter border 

 would give the pectoral fin of Megaptera a proportion of more 

 than a fourth of the total length of the carcase ; that along the 

 inferior border as rather nearer a third than a fourth. In 

 the other great finners the proportion may be put at about 

 an eighth, taken on the lower border. 



The paddle in Megaptera is also of greater breadth than in 

 other finners, though not than in Mysticetus. 1 In the 64-feet- 

 long B. musculus, the greatest breadth was 19 inches, in the 

 50-feet-long one, 16 inches. In this Megaptera it is 32 J inches. 

 The breadth is, however, not greater in proportion to the length 

 in Megaptera than in the full-grown B. musculus, but rather 

 less. 



Another external character of the paddle of Megaptera is the 

 very undulating anterior border, showing two greater and seven 

 lesser nodes (see fig. 1), the causes of which are made clear by 

 the dissection. A few lesser undulations are seen on the 

 ulnar border towards the tip. 



6. DORSAL FIN. The form is shown in fig. 2. There is 

 what may be called the fin proper and the basement, a low 

 elevation from which the fin proper rises abruptly behind and 

 gradually in front. The basement is marked off only by a 

 gradual elevation from the general contour of the back. It 

 extends from about 2 feet behind the tip of the fin proper to 

 about 4 feet in front of it. Height of fin proper 7 inches, of 

 the entire elevation 11 inches. Thickness at the middle of the 

 fin proper, If inches; at base of fin proper, 3 inches ; of basement 

 at its lower part, 12 inches; at 2 feet in front of fin proper, and 

 it mid-height of basement there, 4 inches. In Rudolphi's 



1 Mr Robert Gray informs me that his father, Captain David Gray, this summer 

 caught the largest Right Whale (Balcena mysticetus) he has ever taken, a female 

 57 feet long ; length of the pectoral fin, measured along the middle of the out- 

 stretched fin, on the inner surface, 8 feet 2| inches, greatest breadth 5 feet 1 inch. 



