474 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1907. 
I. Livinc Martnr MammMats. 
1. WHALES. 
A. WHALEBONE WHALES. 
The whalebone whales are not only the giants among living ani- 
mals, but without doubt also the largest marine animals that have 
ever lived. No marine animal of the past has reached the length of 
the northern blue whale (or sulphurbottom, Balenoptera musculus 
L.), which attains 25 to 30 meters (824 to 984 feet). (Fig. 1.) 
Fic. 1.—Blue whale, or Sulphurbottom (Balznoptera musculus L.), Length reaches 
30 meters (984 feet), After Ff. W. True. 
First family, right whales—The best known representative of 
this family is the Greenland whale (Arctic right whale, or bow- 
head), Balena mysticetus LL. Among the most remarkable char- 
acters of this clumsy animal, which reaches a length of 20 meters 
(654 feet), is the enormous head, which alone occupies one-third 
to two-fifths of the total length. The flippers are short, broad, and 
five-fingered. The whalebone is very long and may reach the 
Fic. 2.—California Gray whale (Rhachianectes glaucus Cope). Length reaches 15 
meters (494 feet). After C. M. Scammon. 
extraordinary length of 15 feet in old animals. The belly is entirely 
smooth, and there is no fin om the back. 
Second family, gray whales—This family is represented only 
by the California gray whale (Rhachianectes glaucus Cope), which 
occupies a peculiar intermediate position between the right whales 
and the finbacks, or rorquals. It is nearly as long as the bowhead, 
but the body is more slender and the head is small. (Fig. 2.) The 
