MUSEUM OF COMPARATIVE ZOOLOGY. 43 



In respect to genera, the number existing in the northern and south- 

 ern waters is equal ; there being two of hair seals and one of fur seals 

 at the north, and the same number at the south. One genus, Zcdophus, 

 is found both at the North and South. Eumetopias of the North may be 

 regarded as represented at the South by Otaria; and Callorhinus of the 

 North by Arctocephalus at the South. Callorhinus and Arctocephalus 

 are undoubtedly representative groups ; but if we regard the latter as 

 composed of three intimately related species instead of one, we shall have 

 three species of fur seals at the South against one at the North. Za- 

 lopkus is the most southern genus, its single species on each side of the 

 equator nearly reaching the tropics, if not actually existing within them 

 at Moluccas, as represented by Mr. Murray* in his map of the distri- 

 bution of these animals. Another interesting fact is that on the coast of 

 Asia the northern species of Zcdophus (Z. Gillespii) is well known to 

 inhabit Japan, whilst the home of the southern species (Z. lobatus) in- 

 cludes the shores of Australia and the neighboring islands ; so that the 

 only two congeneric species of the eared seals distributed on opposite 

 sides of the equator are those whose habitats most nearly approach each 

 other. The distribution of the species is further indicated in the follow- 

 ing conspectus, which is designed to give a concise view of the different 

 groups of the eared seals, with their principal distinctive characters, 

 affinities, and the geographical distribution of the species.f 



* Geographical Distribution of Mammals, Map XXVIII, 1S66. 



t The following observations respecting the distribution of the eared seals of the 

 eastern coast of South America have been kindly communicated to me bv Dr. G. A. 

 Maack, who in November and December, 1867, visited the coast of Buenos Ayres for 

 the purpose of obtaining specimens of these animals: 



" The eared seals, of the eastern coast of South America, exist especially between the 

 34th and 40th degrees of south latitude. North of the Rio de la Plata they occur at the 

 Islas de los Lobos, near Maldonado. South of this river they occur in great numbers at 

 the Cabo Corrientes, where they frequent the rocks at the base of the vertical and even 

 overhanging cliffs (160 to 170 feet high) of these shores. I visited the latter locality 

 during the months of November and December, 1867, where I had the opportunity of 

 observing these animals alive. But as Professor Burmeister and myself have already 

 published the scientific results of this excursions [see above pp. 13 and 18], but little 

 requires to be added here. 



"As stated in my paper in ' Der Zoologische Garten ' (Jan., lS70),only two species of 

 these animals exist on the eastern coast of South America: one, the Otaria jubata, 

 from its having but a single kind of hair, is known to the natives as the Lobo marino con 

 unopelo; and the other, Arctocephalus faMmdicus, from having both external hair and 

 under-fur, is called the Lobo marino con dos pelos. Of both I obtained specimens. The 



