40 ODOBJENUS ROSMAEUS ATLANTIC WALRUS. 



to be only differences of a sexual character.* Stanuius,t ten 

 years later, cited the views of Teniniinck and Wiegmann (as 

 above given) respecting sexual differences in Walruses, but adds 

 nothing new to the subject. Lainont (see antea, p. 35) states 

 that the " tusks vary very much in size and shape according to 

 the age and sex of the animal." "Cows' tusks," he says, "will 

 average fully as long as bulls', from being less liable to be broken, 

 but they are seldom more than twenty inches long and three 

 pounds each in weight. They are generally set much closer 

 together than the bull's tusks, sometime overlapping at the 

 points, as in the case with the stuffed specimen- at the British 

 Museum." He gives the length of tusks in the male as 24 inches, 

 and the weight as 4 pounds each. 



A skeleton, marked as that of a female, in the Museum of 

 Comparative Zoology, collected in the Greenland seas by Dr. 

 Kane, has the bones very light, soft, and porous, as compared 

 with those of male specimens. The skull (see figg. 1-3) is much 

 smaller, with the crests and ridges very slightly developed, and 

 the tusks long and slender, and overlapping at the points. This 

 skull, though of a rather aged individual, is 2 to 2^ inches 

 shorter than male skulls of corresponding age, and about 2 

 inches narrower; but these figures scarcely express the real 

 difference between them, owing to the very much weaker devel- 

 opment and slighter structure of all parts of the skull, which 

 certainly has not one-half the weight of average adult male 

 skulls. The weaker structure is especially marked in the lower 

 jaw. The tusks, on the other hand, are several inches longer 

 than in any male skulls of the Atlantic species I have yet exam- 

 ined, but they are so much weaker and slenderer that their 

 weight is more than one-half less. The same difference of light- 

 ness and smaller size extends throughout all the bones of the 

 skeleton, indicating that the size of the animal in life was far 

 less than that of ordinary males. The very great length of the 



* Says Wiegmaiin : "Hr. Fremery fiilirt aii, dass Hr. Temniiiick einen (nach 

 Deutliclikeit tier Nahte) uoch. jmigen Scliiidel des Reiclisinusemns iiiit aus- 

 gezeiciinet laugeii diirmen Stosszalmen fur deu oines Wei.bch.eiis gelialteu 

 liabe. Ich erinnere niich aucli vou Gronlandsfahreii geliort zu liaben, dass sicli 

 das Weibcken dtirch langere, diinnere, das Mannchcn durcli kiirzere, aber viel 

 dickere Stossziilme auszeiclme. Die geriiigere Entwicklung der Hinter- 

 liauptleiste, die geringere Scliwere der Knochen, selbst das Zuriickbleiben des 

 hintersten Backenzaknes iin Oberkiefer komite, wenn es wirklich. uur sexu- 

 elle Verschiedenlieit sein sollte, mit Aiialogieu belegt werden." Arch, fur 

 Naturgcsch., 1832, pp. 128, 129. 



t Mailer's Arch. fiir. Anat., 1844, p. 392. 



