STRANDED ON THE BRITISH COASTS. 



149 



being all of one colour, white or yellow — another distinguishing 

 feature of the same species. The Perranporth Whale was only 

 18 feet long", while that from Ulrome measured 33 feet. The 

 much finer character of the baleen-hairs of the former specimen 

 was thus probably due to immaturity. 



This species is known to occur off the Norwegian coast at all 

 times in the year, and it feeds to a large extent on fish. 



(2) Rudolphi's Rorqual or Sei Whale (Bakenoptera borealis. 

 Less.). 



In my Annual Reports on Stranded Cetacea (1914-1918) I have 

 recorded the following four specimens as belonging to this 

 species : — 



1914, Feb. 28.— Derrynane, Co. Kerry, 60 ft. 

 ,, Sept. 21. — Crosskirk, Caithness, 43 ft. 



Nov. 17. — John o' Groats, Caithness, 47 ft. 

 1917, Oct. 13.— Annet, Scilly Islands, 45 ft. 



These determinations were made mainly on the evidence of 

 single blades of baleen ; and I have to admit that on a re- 

 examination of these specimens, and taking into consideration 

 the other evidence available, I have come to the conclusion that 

 they were probably incorrect in three of the four cases. The 

 mistakes (if they were wrong conclusions) arose principally from 

 the comparison of young specimens with old ones. 



There can be little doubt that the specimen from Crosskirk 

 was' correctly determined. Its baleen-fringes are composed of 

 extremely fine, flexible hairs, which have the curly, wool- like 

 texture which has been noticed by other writers on Rudolphi's 

 Rorqual. In this respect they agree precisely with a series of 

 baleen-plates, 1912.6.25.1 in the British Museum collection, 

 obtained from one of the Shetland Whaling Companies and 

 undoubtedly correctly determined. In the other three specimens 

 which were referred to B. horealis, the baleen-hairs, although 

 relatively fine, particularly in the individuals from John o' Groats 

 and the Scilly Islands respectively, were straight and not curly. 

 The fact that they are finer than those of the large blades of a 

 fully grown Common Rorqual is probably due to immaturity*, 

 and perhaps to the small size of the blades, which may have been 

 taken from near one end of the baleen-series. I am accordingly 

 led to the conclusion that the three individuals in question were 

 Common Rorquals ; and some further evidence in support of this 

 conclusion is forthcoming. 



It was pointed out by G. 0. Sars (1881, pp. 3, 5) that the 

 Common Rorqual is characterized by a very remarkable asymmetry 

 in the coloration of the head, and that this feature is invariable 

 in both sexes and at all ages, at any rate in the Northern 



* See the remarks on this subject under the preceding species. 



