222 FAMILY OTARIIDJE. 



molar is much smaller than either of the others. The middle 

 incisors are replaced early in foetal life by the permanent ones, 

 which are ready to cut the gum at birth. The outer upper 

 incisor remains much longer, persisting quite till after birth, as 

 do also the temporary molars, while the canines are not shed 

 for some weeks, at least five or six weeks. As Professor Flower 

 has observed, " It is very interesting to note that in the Eared 

 Seals (genus Otaria [or family Otariidce]), which more nearly 

 approach the terrestrial Carnivora in many points of structure 

 as well as habits, the milk-teeth are less rudimentary and 

 evanescent than in the true Seals, the canines especially being 

 of moderate size and retained for several weeks."* 



The milk dentition of the Eared Seals has already been de- 

 scribed in two species of Arctocephalus, and I am able to add 

 some account of it in Eumetopias and Zalophus. 



Van Beneden found, in 1871, in a young skull of " Otaria pu- 

 silla"^ ("= Otaria delalandi," Cuv.,= Arctocephalus antarcticus, 

 Allen, ex Thunberg), the Fur Seal of the Cape of Good Hope, the 

 milk dentition to be 1. 1=?, C. ^ M. ~; but he supposed the 

 absence of the other lower incisors to be due to their having 

 already fallen. The two inner superior incisors were much 

 smaller than the outer one, appearing like little white grains 

 stuck upon the gum. The outer had a long slender root and a 

 distinct crown. The canines were comparatively large, with 

 long roots and a lengthened crown, and both the upper and 

 lower were of similar form. The superior molars were sepa- 

 rated by considerable intervals, the first being over the space 

 between the first and second permanent molars, the second over 

 the space between the second and third, and the fourth over 

 the fourth permanent tooth. The middle milk molar he found 

 to be much smaller than either the first or third, the two last 

 named being of nearly equal size, but only the third was double- 

 rooted. The lower milk molars were smaller than the upper, 

 all single-rooted, and held the same position relatively to the 

 permanent teeth as the upper ones. The middle one, as in the 

 upper series, was much smaller than either the first or third. 



Later Malm described the milk dentition of Arctocephalus 

 nigrescens\ (=ArctocepJialus australis) as existing in a specimen 



* Journ. Phys. and Anat., iii, 1868, p. 269. 



t "Sur les dents de lait de 1' Otaria pusilla," Bull, de la Acad. Roy. de Bel- 

 giqne, t. xxxi, 1871, pp. 61-67 (illustrations). 

 JCEfver. af Kongl. Vetensk.-Akad. Forhandl., 1872, No. 7, p. 63. 



