SOME OBSERVATIONS ON ANTARCTIC CETACEA. 505 



but are capable of withstanding very great variations in temperature. There are 

 indications, for instance, that whales migrate from polar to tropical seas, and that in 

 consequence northern and southern species are probably in many cases identical, as 

 has been urged by Sir WILLIAM TURNER and others.* 



* " The Right \\Tiale of the North Atlantic, Balxna bucayensis, etc.," by Principal Sir WILLIAM TURNER, K.C.B., 

 F.R.S., D.C.L., Trans. Hoy. Soc. Edinburgh, vol. xlviii. pt. iv., 1913. 



"The Baleen Whales of the South Atlantic," by Principal Sir WILLIAM TURNER, K.C.B., F.R.S., D.C.L., 

 Proc. Roy. Soc. Edinburgh, vol. xxxv. part i. No. 2, 1914 



EXPLANATION OF PLATES. 



Plate I. Facsimile drawings by Mr W. G. BURN MURDOCH of a piebald porpoise (Lagenorhynchus 



l) taken at the Falkland Islands. 

 Plate II. Photograph of Nordkapper (Balsena biscat/insi*), by Mr J. J. BELL. 



