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 Hensel) 



Length of brain-case 



Length of interorbital region.. 



Rostral region 



Palatal length 



Foramen magnum to palatal 



floor 



Incisors to pterygoid hamuli... 



Zygomatic breadth 



Mastoid breadth 



Lachrymal breadth 



Postorbital breadth 



Postorbital constriction 



Width of rostrum at base of 



canines 



Width of palate 



Width of posterior nares 



Upper tooth row(pm.i-m3.) 



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 



JH. c. z. 

 II25 



^ad. 



233 

 211 



87 



65 



71 



102 



III 



134 



144 



130 



64 



65 



34-5 



51 

 32 

 22 



59 

 34 



3° 

 18 



61.3 



37 

 30-5 



M. C. Z. 



1 126 



^ad. 



235 

 210 



85 

 70 



70 



99 



112 

 137 

 138 



125 

 61 



27 



5° 

 31 

 17 

 56.5 

 37 

 28 

 16 



59 



319 

 30 



Arctocephalus philippii. 



Strait of 



Magellan. 



U.S.N.M. 



23332 



^ad. 



U.S.N.M. 



23279 

 ^ad. 



260 

 230 

 103 

 67 

 84 

 108 



125 

 149 



67 



61 



33 



48 

 34 

 24 

 60 



45 



25 

 12 



52 



41-3 

 34 



Hood Isl., Galapagos. 



260 



245 

 97 

 71 

 90 



III 



125 



150 



132 



112 



64 



60 



26 



51 

 28 



29 



55' 

 50 

 24 

 14 



51 



37 

 34-6 



U.S.N.M. 

 23281 

 J ad. 



272 



238 



96 



75 



88 



108 



no 

 149 

 144 

 122 

 72 



63 

 31 



52 



31 

 28 

 67 

 49 

 25 

 12 



53 



35 

 32-4 



U.S.N.M. 

 23280 

 ^ad. 



265 

 238 



99 



75 



85 



"3 



125 

 152 



143 

 127 



66 



61 



30 



5° 

 36 

 28 

 68 



15 



54 



37-3 

 • 32 



Dr. J. E. Gray, in 1859, based the name Arctocephalus nigyescens 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 Ayctocephalus falk- 

 landicits. In 1874 the same author based the name Euotaria 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- 

 cephalus grayi, the A. falklandicus 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, si.x. 



