186 



ALLEN: NEW ENGLAND WHALEBONE WHALES. 



that to digit I joins the tendon of the remaining flexor, flexor digitorum radialis (or longus 

 pollicis) whose origin is along the proximal two thirds of the radius and the interosseous mem- 

 brane. The presence of this muscle is in support of Kukenthal's contention that digit I is 

 retained, and digit III is the missing one. The function of these muscles is doubtless to give 

 stiffness to the paddle. 



Visceral Anatomy. An account of the anatomy of a male Finback stranded on the 

 English coast, was published by Murie in 1865. It was an adult, 60 feet long, with the epi- 

 physes of the bones fused. The oesophagus is described as 7 or 8 feet long, and of such a 

 diameter that "the closed fist could be passed with ease through any part of its course." In 

 Newfoundland specimens, True (1904, p. 128) found the width of the gullet to be about 7 inches. 

 The stomach consists of four separate compartments, which communicate by round and some- 

 what constricted openings. The first division is large and rounded like a great bag, some 

 99 inches on the greater curvature; the second is more cylindrical, opening from the upper 

 part of the first division, and is about 97 inches long. Its walls are slightly thicker and in both 

 are plicated. The third and fourth divisions are shorter and cylindrical. Immediately below 

 the last cavity of the stomach the hepatic duct enters. The total length of the small intestine 

 of Murie's specimen was 248 feet or four times the length of the whale. The large intestine 

 measured about 40 feet. There is no caecum. 



A remarkable adaptation to aquatic life is found in the Cetacea whereby a projection 

 of the epiglottis extends upward from the pharynx or throat as a tube into the posterior narial 

 opening of the skull, so that a continuous passage is formed from the blowholes to the lungs, 

 and thus effectually prevents the entrance of water into the lungs from the mouth. A similar 

 structure occurs in the Ungulates, so that, as in the horse, they cannot breathe through the 

 mouth. In the whalebone whales, this extension of the air tube is about in the center of the 

 pharynx so that in swallowing, the small fish or minute crustaceans pass on either side. In 

 the toothed whales, as Lillie (1910) has most suggestively shown, the larger size of the food 

 particles has caused the displacement of the epiglottis to the left-hand side of the gullet, leaving 

 a single large opening for the passage of food. The marked bilateral asymmetry of the skull 

 in the Odontoceti, he believes is a result of this displacement. 



Skeleton. The skull of the Common Finback (Plate 11, fig. 2) differs conspicuously 

 from that of the other species of the genus found on our coast, in its long and narrow rostrum, 

 which tapers evenly to a relatively sharp snout. True has shown that the average breadth 

 of the rostrum at the middle is barely a fifth of the total length of the skull. In museum speci- 

 mens the drying of the bones often causes the tips of the maxillaries and intermaxillaries to 

 spread apart, but the long and tapering outline of the former, especially as seen from below, 

 is marked. Viewed from above the frontals appear somewhat trapezoidal in outline; the 

 hinder margin forms nearly a right angle with the long axis of the skull, and the external margin 



