128 



PATAGONIAN EXPEDITIONS : ZOOLOGY. 



Comparative Measurements of the Skulls of Arctocephalus australis and A. philippii. 



Arctocephalus australis. Straits of Magellan. 



Basal length 



Basilar length (of Hansel) .... 



Length of brain-case 



Length of interorbital region.. 



Rostral region 



Palatal length 



Foramen magnum to palatal 



floor 



Incisors to pterygoid hamuli... 



Zygomatic breadth 



^Iastoid breadth 



Lachrymal breadth 



Postorbital breadth 



Postorbital constriction 



Width of rostnim at base of 



2333 « 

 i ad. 



U.S.N.M. 

 36664 

 ,?ad. 



canines 



Width of palate 



Width of posterior nares 



Upper tooth row(pm. J— m^) . . . . 



Nasals, length 



Nasals, width ant 



Nasals, width post 



Ratio (skull) of breadth to 



length 



Ratio of braincase to total 



length 



Ratio of rostrum to total length 



235 

 206 



87 

 70 



75 

 104 



107 

 136 

 142 

 124 



58 

 48 



27 



51 

 28 



17 



58 

 34 

 28 

 12 



60.4 



315 



235 

 211 



85 



66 

 76 

 98 



"3 

 136 

 148 



136 



57 

 59 

 35 



52 

 28 

 16 

 57 

 36 

 30 

 14 



M 



c. z. 

 II25 



^ad. 



M. C. Z. 

 1 126 



^ad. 



233 



211 



87 



65 



71 



102 



235 



210 



85 

 70 

 70 



99 



Arctocephalus ph ilippii. 



Strait of 

 Magellan. 

 U.S.N.M. 



23332 

 Jad. 



260 

 230 

 103 



67 



84 



108 



Hood Isl., Galapagos. 



U.S.N.M. 

 23280 

 J ad. 



51 

 32 



22 



59 

 34 



30 

 18 



(>i 61.3 



3'-5 

 323 



37 

 30-5 



50 

 31 

 17 

 56.5 

 37 

 28 

 16 



59 



319 

 30 



52 



41-3 

 34 



51 



37 

 34-6 



53 



35 

 324 



265 



238 



99 



75 



85 



"3 



125 

 152 



143 



127 



66 



61 



3° 



5° 

 36 

 28 

 68 



15 



54 



37-3 

 32 



Dr. J. E. Gray, in 1859, based the name Arctocephalus nigrescens on a 

 young skull from the Falkland Islands, a "species" he continued to recog- 

 nize in all his later works and papers on the Eared Seals, but which by 

 other writers has been quite as uniformly referred to Ayctocephahis falk- 

 laudicus. In 1874 the same author based the name Eiiotaria latirostris 

 on a skull also supposed to have come from the Falkland Islands, making 

 the third species recognized by him from these islands. In 1873 Mr. A. 

 W. Scott added still another synonym by avowedly renaming, as Arcto- 

 cephalns gyayi, the A. falklaudiciis of previous authors. In 1887 Nehring 

 based the name Arctocephalus gracilis on skulls of young examples taken 

 on the coast of Rio Grande do Sul ; and in 1892, Philippi described and 

 figured a very young specimen, under the name Otaria brachydactyla, 

 from the Chonos Archipelago, which may or may not be referable here. 



' Only five molars instead of the normal number, six. 



