I20 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



"Description Physique de la Republique Argentine," gave a series of 

 figures of skulls of old and young of both sexes, showing individual and 

 sexual variation, and also variation due to age. This is a most important 

 series of figures, based on specimens from the Lobos Islands, off the 

 mouth of the Rio de la Plata. 



In 1892 Philippi figured a number of skulls, including those of three 

 supposed new species, all, however, based on very young animals, several 

 of the skulls showing part of the milk dentition, besides other features 

 of immaturity. 



Otaria byronia has thus been very fully and satisfactorily illustrated as 

 regards both its external characters and internal structure. 



Genus ARCTOCEPHALUS F. Cuvier. 



Arctocephale, F. Cuvier, Mem. du. Mus. d'Hist. Nat, XI, 1824, 205, pi. 



XV, fig. I , ^, b, c. 

 Arctocephalus F. Cuvier, Diet, des Sci. Nat, XXXIX, 1826, 554. Same 



as above. Type, " Phoca ursiua^' = PJwca autayctica Thunberg. 

 Halarctus Gill, Proc. Essex Inst., V, 1866, 7, 11. Type, Arctocephalus 



delalandi Gray = Phoca antarctica Thunberg. 

 Arctophoca Peters, Moriatsb. Akad. Berlin, May, 1866, 276 (subgenus 



of Otaria). Type, Otaria [Arctophoca'] philippii, sp. nov. 

 Eiwtaria Gray, Ann. & Mag. Nat Hist (4), IV, Oct., 1869, 269 ("South 

 America") ; Suppl. Cat Seals and Whales, 1871, 20. Type and only 

 s'^tcxts, Arctocepha/us nigrescens Gv2iy = Phoca fa/k/andica Shaw. 

 Gysophoca Gray, Ann. & Mag. Nat. Hist. (4), IV, Oct., 1869, 269 

 ("Australia"); Suppl. Cat Seals and Whales, 1871, 24. First spe- 

 cies, Otaria {Arctocephalus) cinerea Peters = ? Otaria cinerea Peron, 

 1816= Otaria cinerea Quoy & Gaim., \'^2P = Otaria for steri Lesson, 

 1828. 

 The only species referred by F. Cuvier (/. c, 1826) to his genus 

 Arctocephalus is his ''Arctocephalus ursinus ; Ursus marinus, Steller, 

 Novi comment, petrop., 11, p. 331," which he elsewhere mentions as 

 " Phoca ursina, Linn.," and distinctly says is the type of his genus Arcto- 

 cephalus} On this account many subsequent writers have given the type 

 of Arctocephalus as Phoca ursina. Under this name, however, Cuvier 

 associated not only Steller's Sea Bear, but the Fur Seal observed by Per- 



'Mem. du Mus., XI, 1824, p. 208; Diet, des Sci. Nat, XXXIX, 1826, p. 553. 



