242 MERISTIC VARIATION. [Px^rt i. 



as lA In each case the extra tooth is placed a little within the arcade 

 though the adjacent teeth are also spaced out for it. This skull has 

 been a good deal mended. C. S. M., 990. 



331. Phoca grocnlandica : in right upper jaw p^ is smaller than the corresponding 

 tooth of the left side, though it is two-rooted as usual. Between it and pI there is 

 a small, peg-like, supernumerary tooth. Both p^ and the extra tooth bite between 

 pi and m 1 of the lower jaw. Leyd. M. 



332. P. grocnlandica: supernumerary tooth with two roots placed internally to and 

 between left & and m\ The last molars stand at the same level on the two sides. 

 B. M.,328, i. 



333. Zalophus lobatus: in right upper jaw a supernumerary tooth placed on the 

 outside of the arcade on a level with the interspace between p* and p 4 . This tooth 

 resembles p 4 or m 1 . On the left sidep 1 is smaller than on right side and a supernu- 

 merary tooth which is still smaller stands between p^ and the canine. Leyd. M. 

 [given above, No. 323]. 



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

 between pi and pi. In size and form it agrees very nearly with the first premolar 

 of the right lower jaw: other teeth normal. C. M., 903, F. 



335. 3P. vitulina: in front of p* on left side the teeth are all lost but there has been 

 some irregularity, probably a supernumerary tooth level with pi : also behind right 

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

 merary molar. C. S. 31., 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. 61) 



Fig. 61. Phoca vitulina No. 336, a profile of the left teeth in the bite as seen 

 from within. 



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

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

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

 therefore not a copy of m 1 , which has 4 — 5 cusps. C. S. M., 1067. 



'337. Halichoerus grypus : of 47 skulls seen, 12 have one or more 

 supernumerary molars. One case of p% , m§. Nehring, Sitzb. 

 naturf. Fr. Berlin, 1883, p. 110. 



2 2 



Of 34 skulls in Greifswald Museum there were 3 cases of m ^ , 



and five cases of m\ on one side only. Ibid., 1882, p. 123. 



Of 11 skulls seen by myself two individuals (C. M.) have an 

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

 placed at a considerable distance behind »£ as they are in Otaria. 

 [In addition to these Gray figures a skull with m\ but without 

 allusion to this fact in the text. Hand-list of Seals in B. M., 

 1874, PL vil] 



