242 M ERISTIC VARIATION. [PART I. 



a- y 1 . Iii each c;isf tin- extra tooth is placed a little within the arcade 

 though the adjacent tn-tli an- also spaced out for it. This skull has 



been a ;_">'"l deal mended. C. S. M., 990. 



331. Phoca groenlandica: in ri^'lit upper jaw 7^ is smaller than the corresponding 



1 of tin left side, though it is two-rooted as usual. Between it and p? there is 

 a siii;ill. jn-^-likf, Mi]H rniiiin i.u-y tooth. Both pj and the extra tooth bite between 

 ,, mid ,' of the lower jaw. Li-ijd. M. 



332. P. grocnlandica : .-U]M nuimerary tooth with two roots placed internally to and 

 between left /'' and <\ The last molars stand at the same level on the two sides. 

 B. M..32S, i. 



333. Zalophus lobatus: in ri<iht upper jaw a supernumerary tooth placed on the 

 iiti<i'l<' of tin- ;tn-;ule nn a level with the interspace between p* and p*. This touth 



or in 1 . On the left side p 1 is smaller than on right side and a supernu- 

 ineiaiy tniith wliieli is still smaller stands between p^ and the canine. L/'ijd. M. 

 [given above, No. 323]. 



P. vitulina: in right lower jaw a supernumerary tooth inside the arcade, 

 between J: :nnl /,-. In size and form it agrees very nearly with the first premolar 

 of the ri(_'ht lower jaw: other teeth normal. C. M., 903, F. 



335. P- vitulina: in front of ^ on left side the teeth are all lost but there has been 

 some irregularity, probably a supernumerary tooth level with j^: also behind ri;_'ht 

 wl there is a small tubercular nodule of bone which may perhaps cover a supernu- 

 merary molar. C'. .S'. J/., 1064. 



Molars. 



336. P. vitulina : on left side there is a small supernumerary molar 

 placed behind ''. This tooth stands in the line of the arcade (Fig. 01) 



m 2 



Kni. c,l. rhora rititlina No. 33G, a profile of the left teeth in the bite as seen 

 from within. 



but is turned si. that its greatest width is set transversely to the jaw. 

 Tn the lower jaw of the same side there is a supernumerary tooth placed 

 internally to ,'. This tooth has two roots and three cusps, and is 

 therefore not a copy of , n \ which has 4 5 cusps. C. S. M., 1007. 



*337. Halichcerus grypus : of 47 skulls seen, 12 have one or more 

 siipi-niiiiin-riiry molars. O ne case of p , TH|. NEHRING, Sitzb. 

 nut a if. /'/-. Berlin, issrj, p. 110. 



< )f:{4 skulls in ( Jivit'swald .Museum there were 3 cases of m 



1- -1' 



and live cases of n,-i (.1 side only. Ibid., 1882, p. 123. 



Of 11 skulls .seen l.y myself two individuals (C. M.) ha\c an 

 extra molar on left side. In these eases the extra teeth are 

 placed at^a considerable distance behind ^ as they are in Oturin. 

 [In addition to tlies,' CKAY figures a skull with wf but without 

 allusion (,, this fact in the text. ll<tml-Uxt of Seals in B M 

 L874, I'l. vii.] 



