1 8 MAMMALIA. 



evidently nearly allied to the living Walrus, and called them 

 specifically after Prof. Huxley. Subsequently (ibid., Vol. XXVI., 

 p. 511, 1876) he called attention to a portion of a tusk from the 

 Belgian Pliocene, which Prof. Yan Beneden had shown him in 

 1864, and to the descriptions by the Vicomte Du Bus (Bull. Ac. 

 Koy. Belg., Vol. XXIV., p. 566, 1867) of Alachtherium Cretsii. 

 The tusk he thought agreed in form with the Suffolk specimens. 

 Again, in 1882 Prof. Lankester (Trans. Linn. Soc., Ser. 2., Zool., 

 Vol. II., p. 213) read a paper reviewing the genus, and showing 

 reasons for including these Crag tusks in the recent genus Tri- 

 chechus; but retaining for them the specific designation T. 

 Huxleyi. He pointed out also that the English Crag tusks could 

 not be referred to either Alachtherium Cretsii or Trichecodon 

 Koninckii, both of which had been established on parts of 

 skeletons without tusks, whilst T. Huxleyi had been founded on 

 tusks alone, and moreover the latter has the priority, even if these 

 Belgian forms should prove to be identical with the Suffolk 

 species. 



Some of the Cra tusks are much compressed, as shown by 

 specimens in the Museum of Practical Geology ; and Mr. Frank H. 

 Harris, of Abingdon, has a portion of a small flattened tusk, from 

 the Red Crag of Foxhall, probably of a young specimen, which is 

 provisionally referred to the present species. It is about 80 mm. 

 long, 31 mm. from back to front, and 16 mm. wide. The trans- 

 verse section is ellipitical, being thickest towards the back or con- 

 cave margin, and narrower towards the front or convex margin. 

 The centre of this tusk is occupied by a considerable area of 

 globular dentine. 



Trichechus Huxleyi is chiefly known by specimens from the 

 Nodule-bed of the Red Crag of Suffolk ; it has also been recog- 

 nised in the Forest-bed near Cromer (Mem. Geol. Surv. Vert. 

 Forest Bed, p. 26, 1882), and there is the proximal half of a 

 Trichechus femur in the Norwich Museum, obtained by Dr. 

 Crowfoot and Mr. E. T. Dowson in the Chillesford beds at 

 Aldeby, which differs from the femur of the living T. rosmarus, 

 and may be provisionally placed with the present species. Pos- 

 sibly the portion of tusk found in the Belgian Pliocene, and 

 alluded to by Prof. Lankester, may also belong to this species. 



Genus PHOCA, Linnaeus. 

 PLATE II., FIG. 1, , b. 



A humerus from the Norwich Crag of Bramerton, which is now 

 in the Norwich Museum, was identified, some years since by Prof. 

 FJower as belonging to a Seal ; but he did not name it specifically. 

 It is the one alluded to by Mr. H. B. Woodward (Mem. Geol. 

 Surv., Geology of Norwich, p. 55, 1881), and probably 

 Messrs. R. and A. Bell (Proc. Geol. A^soc., Vol. II., p. 212, 



