78 BULLETIN OF THE 



Measurements. — The preceding table of external measurements indi- 

 cates the general size of the adult males and females, and the young at 

 thirty-five days old. In some respects the dimensions are only approxi- 

 mately correct, being taken from mounted specimens ; in the main, how- 

 ever, they are sufficiently accurate. A few measurements taken from the 

 soft skin are also given ; the making of a complete series of measurements 

 of the skins before t£3fey were mounted was accidentally omitted. In ad- 

 dition to the six specimens of Captain Bryant's collection, I am indebted 

 to Mr. W. II. Dall for measurements of a male and a female, taken by him * 

 from the animals immediately after they were killed. The female (said by 

 Mr. Dall to be six years old) is evidently adult, but the male, from its 

 but little larger size, seems not to have been fully grown. In the last 

 column of the table a few measurements are given of a male specimen of 

 the A rctocephalus falklandicus, taken by Dr. G. A. Maack, from a fresh 

 specimen collected by him at Cabo Corrientes, Buenos Ayres. This speci- 

 men appears also to have not been fully grown. 



Skull.] — In adult specimens the breadth of the skull is a little more 

 than half its length, the point of greatest breadth being at the posterior 

 end of the zygomatic arch. The muzzle or facial portion is broad and 

 high, or greatly produced, much more so even than in Eumelopias. The 

 postorbital processes vary from sub-quadrate to sub-triangular, sometimes 

 produced posteriorly into a latero-posteriorly diverging point, as in Zalo- 

 phtis. The postorbital cylinder is broad and moderately elongated. The 

 postorbital constriction is well marked, giving a prominently quadrate 

 form to the brain-case, the latero-anterior angles of which vary somewhat 

 in their sharpness in different specimens. The sagittal and occipital 

 crests are well developed in the old males, nearly as much as in Eumeto- 

 pias, as are also the mastoid processes. The palatine bones terminate 

 midway between the last molar teeth and the pterygoid hamuli ; their 

 posterior outline is either slightly concave, or deeply and abruptly so. 

 The palatal surface is flat, but slightly depressed posteriorly, and but 

 moderately so anteriorly. The zygomatic foramens are broad, nearly 

 triangular, and truncate posteriorly. The posterior and anterior nares 

 are of nearly equal size in the males, with their transverse and vertical 

 diameters equal ; in the females the posterior nares are depressed, their 

 transverse diameter being greater than the vertical. The nasal bones are 

 much broader in front than behind. 



The lower jaw is strongly developed, but relatively less massive than 



* At St. George's Island, Alaska, August, 1868. 



t See Figs. 1-4, PI. II (males); Figs. 1-4, PL HI (females); and Figs. 5, 6, 7, PI. II, 

 and Fig. 9, PL 111 (young). 



