THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 229 



In both Eschricht's figure of the Greenland Humpback (37, pi. 3, fig. 4) and 

 Struthers's figure of the Tay River whale (87, pi. 3, fig. 6), there are 10 anterior 

 tubercles, one for the carpus, or distal end of the radius, 3 for the 2d digit, and 

 6 for the 3d digit. 



There were exactly the same number and the same arrangement in the New- 

 foundland adults and in the fretus taken from Newfoundland specimen No. 21. 

 In the foetus from Newfoundland specimen No. 6, there are 11 projections, with the 

 same arrangement, i. e., one large proximal one, then 2 moderate-sized, then one 

 large, and finally 7 small, including the tip of the fin. 



Eschricht's figure of the foetus of the Keporlcale, or Greenland Humpback, 

 shows 8 small protuberances at the extreme distal end of the posterior, or ulnar, 

 margin of the pectoral. The foetus of Newfoundland specimen No. 21 has the same 

 number. In addition there are two large elevations near this margin (which can 

 hardly be compared with those on the anterior margin), one opposite the pisiform 

 cartilage, or the distal end of the ulna, and one at the distal end of the 5th digit. 

 These are not represented in Eschricht's figure. 



The protuberances of the anterior, or radial, margin and those at the end of the 

 ulnar margin are preserved in the adult, and give the fin its remarkable outline. In 

 most specimens each protuberance is occupied by a cluster of barnacles. The clus- 

 ters are often confluent on both sides of the distal extremity of the fin, forming a 

 continuous edging. They are always surrounded by black. The proximal two 

 thirds of the posterior margin of the fin is nearly free of barnacles. This margin 

 presents a sigmoid curve, convex proximally, concave distally, with the tip directed 

 backward. Except at the distal end, this margin is even and thin, contrasting 

 strongly with the thick, sinuous anterior margin. 



The same peculiarities are seen in the Tay River (Scotland) whale, Sars's Fin- 

 mark specimen, and Eschricht's Greenland specimen, and in the young female 

 from Cape Cod, Mass., in the National Museum (pi. 41, fig. 6). 



In four European Humpbacks, as seen by examining the table on p. 223, the 

 pectoral fin, measured from the head of the humerus, bore the following proportion 

 to the total length : 



Finmark 30.8 $ Cocks 



Ireland 31.5 % Warren 



Tay River, Scotland 31.6 % Struthers 



Dee River, England 32.0 % Moore 



Rawitz gives the following as the relative length in four Humpbacks measured 

 by him at Bear Id. (74, 82) : 



(1) 35.7 %; (2) 32.3 % ; (3) 31.7 %\ (4) 35.3 %. 



In the three Newfoundland Humpbacks which I measured the proportion was 

 as follows : 



(1) 30.3 % ; (2) 33.4 % ; (3) 33.6 %. 



It thus appears that there is a very considerable variation in the length of the 

 pectoral fin in both European and American Humpbacks. Rawitz's largest meas- 

 urements are larger than any others I have found. 



