172 



THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



not so unimportant variations. Its size also can differ in a high degree in different 

 individuals. In some examples it was noticeably smaller in proportion than in 

 Malm's specimen, so that it could be taken for an insignificant process or point pro- 

 jecting from the dorsal keel. In other individuals it was more developed, now 

 more erect, now more strongly curved backward, though without ever approaching 

 near the size it has in the other Finbacks." 



The same range of variation of form was found in the dorsal fin of the New- 

 foundland Sulphurbottom, as will be seen by consulting text figs. 37-42. The 

 following variations were observed : 



O 



No. 1. Female. Dorsal strongly recurved ; tip regularly rounded ; posterior 

 margin deeply concave. (Text fig. 39.) 



No. 2. Male. Dorsal erect, triangular; tip sharp; posterior margin straight. 

 (Text fig. 42.) 



No. 3. Female. Dorsal intermediate in curvature between those of Nos. 1 

 and 2 ; neither so recurved as in No. 1, nor so straight as in No. 2. 



FIG. 37. 



FIG. 38. 



FIG. 40. 



FIG. 41. 



FIG. 42. 



FIG. 43. 



FIG. 44. 



DORSAL FIN OF BALMNOPTERA MUSCULUS (L.) 



FIG. 37. No. 14, S , BALENA STATION, NEWFOUNDLAND. FIG. 38. No. 22, <} , ditto. FIG. 39. No. r, 

 FIG. 40. No. 7, a, ditto. FIG. 41. No. n, $, ditto. FIG. 42. No. 2, $, ditto. FIGS. 43 

 AND 44. ICELAND. (FROM HAI.LAS.) 



, ditto. 



No. 4. Female. Dorsal almost exactly as in No. 1. 



No. 5. Male. Dorsal bad been injured and also had a semicircular piece 

 missing from the posterior margin, as if cut out by a bullet. 



No. 7. Male. Dorsal moderately recurved ; tip quite sharp; posterior margin 

 deeply concave. (Text fig. 40.) 



No. 11. Male. Dorsal large, erect, rather sharp at the apex ; posterior margin 

 moderately concave. (Text fig. 41.) 



