300 THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 
between the navel and anus; some entirely white spots on the posterior ends of the 
abdominal ridges. 
Pectorals gray on the upper surface except at the tip, usually with some 
lighter blotches; white on the lower surface, anterior margin, and tip. Dorsal fin 
dark gray, usually with whitish center crossed by light vertical, curvilinear markings. 
Flukes gray above and below ; the lower surface with fine light and dark gray lines 
running antero-posteriorly. 
Whalebone entirely black. 
Rostrum of the cranium very broad; free margin of maxille convex ; nasals 
oblong, with truncated anterior margin. Vertebral formula: C.7,. DB: 15 (E16); 
L. 14 (-16), Ca. 26 (-28). Total, 63-65. 
BaL@{Noprera Puysawus (L.). 
Common Finbach. Plate 48, fig. 1. 
Form remarkably slender, size large. Head narrow and pointed. 
Average total length, 59 feet; maximum, 81 or 84 feet (?). 
Peectorals, from head of humerus, 12 per cent. of the total length, lanceolate, 
pointed. Dorsal fin moderate; its height about 24 per cent. of the total length ; 
more or less faleate; situated just posterior to line of anus. 
Color of the body dark gray above, white below; the two colors merging by 
imperceptible gradations on the flanks. Coloration of the head not bilaterally 
symmetrical, there being more white on the right side than on the left, at least as 
far back as the pectoral; right ramus of the mandible white externally, and also 
the anterior third, or more, of the whalebone; left ramus of the mandible and left 
whalebone dark gray. Dorsal fin dark gray like the back. Pectorals gray on 
dorsal surface, white on ventral surface and anterior margin. “Flukes dark gray 
above, white below, with gray posterior margin. Gray of the flanks extending 
obliquely downward and backward from the pectorals toward the flukes, but not 
reaching the inferior margin of the caudal peduncle, where there is a narrow white 
edge, bounded anteriorly by a linear gray mark directed obliquely forward and 
downward toward the anus. 
Whalebone gray striped longitudinally with yellowish white in varying pro- 
portions; anterior whalebone on right side of body all yellowish white. 
Rostrum of the skull narrow and acuminate; free margins of maxilla nearly 
straight. Nasals narrow, and pointed anteriorly in the median line. Vertebral 
formula: C. 7, D., 15 (-16), L. 14 (-15), Ca. 25 (-26). Total, 61-63. 
BALANOPTERA BOREALIS Lesson. 
Pollack whale. Plate 49, fig. 2. 
Form moderately robust. Size moderate. Average total length, 46 to 47 feet; 
maximum, 54 feet. Pectorals, from axilla, 11 per cent. of total length, slender and 
pointed. Dorsal large, high, and falcate; vertical height about 4 per cent. of the 
total length; situated just anterior to the line of the anus. 
