292 ALLEN: NEW ENGLAND WHALEBONE WHALES. 



An excellent photograph of two living Pacific Humpbacks in which the extremes of form in 

 the dorsal fin are shown, is published by Andrews (1909, Plate 34, fig. 2). 



The flukes are rather broad, and set at an angle of nearly 45 degrees to the axis of the body. 

 Posteriorly there is a deep median V-shaped notch as in the Fin Whales. The hinder margin is 

 remarkable for its toothed or serrate appearance, due to irregular projections, of which the 

 longest are along the terminal half. These suggest by their appearance some injury to the edge 

 of the flukes, but are in reality wholly normal, since they are present in a large-sized foetus. 



The outline of the caudal peduncle is broken by a rounded protuberance just behind the 

 anus, terminating in a deep transverse groove, and succeeded by a second compressed elevation. 

 Anterior to the anus in both sexes is a rounded elevation, which in the male, contains the penis 

 (True). 



Struthers describes well developed nipples in a male specimen, situated one on each side, 

 a foot and a half behind the preputial opening and two feet in front of the anus. Each is 

 ^•^ enclosed within a shallow pouch whose opening is protected by a soft fleshy projection. 



The ear opening is a small hole, rather ovoid in shape, and about large enough to admit 

 "a rather small-sized uncut goose-quill" (Struthers). In the specimen described by Struthers 

 it was situated "17 inches behind the posterior canthus of the eye-lids, and 2 to 3 inches 

 below the level of the eye." 



Vestiges of Teeth. — In a foetus 35 inches long, Eschricht (1849, Plate 4) has described 

 and figured the vestigial teeth, which are arranged as in the toothed whales, in a long series in 

 each jaw. They are small and bluntly conical, 28 on a side in the upper jaw, 42 on each side 

 in the lower (in a 45-inch specimen) and in some cases were double-rooted. These are all 

 that remain of a once functional set of simple teeth, and indicate the derivation of this and 

 other whalebone whales from toothed whales. These embryonal teeth are resorbed and dis- 

 appear before birth. 



Weight. — There are very few data as to the weight of these great mammals. Goodall 

 (1913) writing of the Humpback Whale of the Indian Ocean, says that the whalemen reckon 

 its weight as approximately a ton for each foot of length, so that a 45-foot whale would weigh 

 about 45 tons. The basis of this computation is not related, but it may be a too liberal allow- 

 ance. Guldberg (1907) has tried to compute the weight by considering the body of the whale 

 as similar to a solid composed of two cones base to base, of which the combined length and 

 greatest diameter are to be measured and the volume, and thus the weight, obtained by a mathe- 

 matical formula. The specific gravity of the whale is considered the same as that of water. 

 This computation gives a weight of about 18 tons for a 40-foot Humpback ( = 18,283 kilograms), 

 which is of course approximate only. A newly-born calf, taken in the Indian Ocean, is said 

 by Goodall (1913) to have measured 16 feet in length and to have weighed two tons. 



Color. — A young female taken at Provincetown, Mass., in 1879, is described by True as 

 having the upper surface of the head, body, and flukes black; " the upper surface of the pectoral. 



