230 THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



THE CAUDAL FIN, OR FLUKES. 



The caudal fin in the Newfoundland Humpbacks has a regular, thick, convex 

 anterior margin, and a thin, sinuate posterior margin, with numerous small finger- 

 like processes, with deep emarginations between them. The tips are recurved. In 

 the fcetuses of No. 21 and No. 6 the processes of the posterior margin were very 

 numerous, prominent, and acuminate, producing a singular fringed appearance. It 

 is evident that this appearance in the adult is not the result of injury, but a natural 

 chai-acter. In the 30-foot specimen from Cape Cod, Mass., in the National Museum, 

 these processes are very numerous and conspicuous (pi. 40, fig. 2). They were also 

 found in the adult Newfoundland specimens. 



The same shapes and processes are seen in Struthers's figure of the flukes of the 

 Tay River whale, in Sars's Finmark specimen, and in Eschricht's figure of a foetal 

 Greenland Humpback. The tips of the flukes are commonly occupied by barnacles. 



OUTLINE OF THE CAUDAL PEDUNCLE. 



That portion of the body between the anus and flukes (called " the small " by 

 whalers), which corresponds to the tail in land mammals, has a straight superior 

 margin, but the inferior mai'gin is broken by depressions and elevations. 



In the Newfoundland female No. 21, the sexual orifice is surrounded by thick 

 protuberant walls, causing a convexity in the inferior outline of the body. The 

 orifice is preceded by a transverse groove, and terminates posteriorly in a hemi- 

 spherical boss, behind which is a second transverse groove in which the anus is 

 situated. Behind the auus is a rounded elevation, terminated by a third deep trans- 

 verse groove and followed by a prominent compressed elevation or carina. The 

 same arrangement of parts is found in female No. 6. (See pi. 39, fig. 3.) In male 

 No. 5, the outline is similar. The penis is contained in a rounded elevation, and 

 another keel-like, compressed elevation appeal's behind the anus. These elevations 

 are also seen in a photograph in the National Museum representing a male Hump- 

 back at Provincetown, Mass. (See pi. 40, fig. 1.) 



Exactly the same form is represented in Sars's figure of a Finmark female as 

 occurred in the Newfoundland females. 



EYE. 



Rawitz (74, 79) states that in the Humpbacks examined by him at Bear Id. 

 the iris of the eye was dark brown, the pupil kidney-shaped, with the long axis foi'e 

 and aft. 



WHALEBONE. 



The whalebone of the European Humpback is described by Van Beneden as 

 black, with black bristles; but this is not correct. Sars (50, 11) describes it as 

 " all, as well on the upper as the lower side, of uniform gray-black color, with some 

 lighter fibres." Struthers's description is more detailed, as follows (57, 13) : 



