Cranium of a DucJc, from the Pliocene Beds, Fifeshire. 387 



for the projection of the upper jaw. It would likewise appear, 

 both from the fossil and from Macgillivray's statement, that the 

 head is larger in the young animal, in proportion to the body, 

 than it is in the adult. Macgillivray does not give the length 

 of the lower jaw of his specimen ; but it will be seen, from the 

 length of that organ already given, that in the fossil the extra 

 size is in the cerebral portion of the cranium. In Prof. Owen's 

 description of the skull of P. Groenlandica*, which was originally 

 figured by Home, and previously referred to, he speaks of " the 

 principal cusp in all but the last lower molar having one acces- 

 sory basal cusp in front, and two behind. According to Cuvier's 

 statement in the ' Ossemens Fossiles,' this was likewise the 

 cranium of a young animal. The truth would seem to be, that 

 the cusps vary somewhat with age, and of course the number 

 given by an author will depend much upon whether the animal 

 he is describing be old or young. The dorsal vertebrse of P. 

 Grcenlandica, as described by Prof. Owenf, appear to correspond 

 nearly with those of the fossil. The neural arches, he observes, 

 of the middle dorsal vertebrae " are without spines, and are very 

 nai'row, leaving wide unprotected intervals of the neural canal.'' 

 He also states that there are " metapophyses developed on the 

 last five dorsal vertebrae." The vertebral formula, however, is 

 somewhat different : he gives 4 sacral and 8 caudal for his spe- 

 cimen. In the fossil there are 3 sacral and 13 caudal (allowing 

 Cuvier's opinion to be correct, that there are 4 sacral in the Seals 

 when the animal is adult, there would still be 12 caudal), and 

 metapophyses are only developed on the last 4 dorsal vertebrae. 

 Whether these and some other minor characters are of sufficient 

 specific importance to separate the fossil from P. Grcenlandica I 

 must meantime leave to those possessed of the requisite know- 

 ledge of the subject to determine. In 1860 there was a right 

 humerus of a Seal found in the red clay of the Gar Bridge Tile- 

 works : this clay is about 50 or 60 feet above the level of the 

 sea, and some four miles west from St. Andrew's. This bone had 

 belonged to a larger Seal than the preceding, but, except in its 

 larger size, it does not differ from the humeri of the latter in 

 any appreciable way ; there are the same strongly pronounced 

 deltoid ridges and the prominent inner tuberosity observable in 

 both ; they are likewise similar in having the inner condyle per';- 

 forated for the passage of the cubital artery. 



About the time that the last-mentioned Stratheden Seal was 

 found, there were likewise discovered, in the same clay-bed, 

 some bones apparently belonging to two genera of Ducks, which 



* Catalogue, Osteological Series, Royal College of Surgeons, vol. ii, 

 - t Op. cit. . 



