580 DR. EINAlt LONNBERG ON THE [Mar. 15, 



3. On the Variation of the Sea-Elephants. 

 By Dr. Einar Lonnberg, (J.M.Z.SS. 



[Received February 25, 1910.] 



(Text-figures 55 & 56.) 



Four years ago, when I wrote about the Sea-Elephant of South 

 Georgia*, the question arose in my mind whether the Sea- 

 Elephants inhabiting the widely separated islands in the southern 

 subantarctic seas all belonged to one and the same race. It 

 appeared to me most probable that this was not the case, because 

 the herds of the different islands are, and must have been for a very 

 considerable time, completely isolated from each other, as these 

 animals are not pelagic in their habits, but chiefly confined to the 

 waters surrounding the islands on the shores of which they 

 spend a great part of their lifetime. As, however, 1 had not 

 sufficient material from different localities for comparison, and the 

 literature did not contain enough to throw satisfactory light on 

 the matter, I had to leave it unsolved. It was therefore a great 

 satisfaction to me when my friend Mr. R. Lydekker took up this 

 question last year and published a paper "On the Skull- Characters 

 in the Southern Sea-Elephant."' t Having read that paper, 

 however, it appeared to me that the characters on which Lydekker 

 has based the racial differences which, according to his views, exist 

 between the Sea-Elephants belonging to four different geographic 

 groups with subspecific value were rather unsatisfactory, when I 

 considered the variation found in skulls of these animals which 

 I had studied from material brought from South Georgia. 



In the paper quoted Lydekker diagnosed the following races : — • 



" 1. Macrorhinus leoninus typicics, Juan Fernandez." 



" 2. M. l.fcdclandicus, Falkland Islands." 



" 3. M. I. macquariensis, Macquarie and (?) Chatham Islands." 



" 4. M. crosetensis, Crozet and (?) Kerguelen and Heard 

 Islands." 



According to later information Lydekker presumes that the 

 Sea- Elephant of Juan Fernandez belongs to the same geographic 

 group as those known under the specific name angustirostris, which 

 latter name then should "be regarded as a synonym of leoninus, 

 while falclandicus would become the substantive name for the 

 Southern species " (I. c. p. 606). 



Lydekker bases the subspecific differences between the Sea- 

 Elephants from the different islands on certain proportions and 

 other characteristics of the skulls selected from the palatal 

 surface. To prove the difference, in proportions he quotes certain 

 measurements in English inches from which the relations in 



* K. Sv. Vetensfcaps-Akad. Handl., Bd. xl. 

 f Proc. Zool. Soc. 1909, pt. iii. p. 600. 



