APPENDIX 



dorsal fin is moderate in height and falcate; it is situated 

 just behind the line of the anus. Many ventral folds. 



The color of the body is dark gray above and white 

 below, the two colors merging imperceptibly into each other 

 on the flanks. The coloration of the head is not bilaterally 

 symmetrical, there being more white on the right side than 

 on the left. The right side of the lower jaw is white and 

 also the anterior third of the whalebone; the left side of 

 the lower jaw and left baleen are dark gray. The gray of 

 the flanks extends obliquely down and back from the pec- 

 toral fins toward the flanks, but does not reach the inferior 

 edge of the peduncle, which is white. 



The pectoral fins are gray above and white below. The 

 flukes are dark gray above and white below, with a gray 

 posterior margin The whalebone is gray, striped longi- 

 tudinally with yellowish white in varying proportions; the 

 anterior baleen on the right side is all yellowish white. 



The rostrum of the skull is narrow and pointed with the 

 free margins of the maxillae nearly straight. The nasal 

 bones are narrow and pointed on the median line anteriorly. 

 Vertebral formula: cervicals 7, dorsals 15 (-16), lumbars 

 14 (-15), caudals 25 (-26). Total, 61-63. Habitat: cosmo- 

 politan. 



SEI WHALE, RUDOLPHFS RORQUAL 

 Balcenoptera borealis (Lesson) 



Moderate size. Average total length, 42 to 43 feet; maxi- 

 mum length, 53 feet. The dorsal fin is large, and falcate; 

 it is situated just anterior to the line of the anus. Many 

 ventral folds. 



The color of the head and back is dark gray ; on the sides 

 and flanks the gray of the back becomes lighter and the 

 flanks are beautifully marked with wavy gray lines. The 

 throat and breast are white, but a wide dark gray band runs 

 across the belly. The ventral line from the anus to the 

 flukes is gray. The pectoral fins above and below are dark 



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