^^^' 55'] MAMMALIllf HUMERUS FROM TONBRIDGE. 413 



26. On the Distal End of a Mammalian Humerus from Tonbridge 

 {Hemiomus major). By Prof. H. G. Seeley, F.B-.S., F.L.S,, 

 P.G.S. (Read May 24tli, 1899.) 



Mr. R. D'A. Anderson, of the Royal Indian Engineering College, 

 lias submitted to me the distal end of the right humerus of a 

 mammal for determination. The bone was found in August 1898 

 by Mr. Grenyille Anderson, on the bank of the River Med way near 

 Tonbridge (at a time when the river was running very low), when it 

 was seen projecting from the reconstructed rock. The locality is 

 not far from Messrs. Curtis & Harvey's gunpowder-mills, at a point 

 between a broken and disused lock-basin and an old bridge near the 

 ballast-pit. On visiting the spot I found fragments of flints among 

 the materials which form the river-banks ; but although this might 

 support a reference of the specimen to any geological period of 

 subsequent date, there are conditions of mineral structure and 

 osteological character which incline me to believe that the bone has 

 been derived from the Weald Clay. 



When the fossil came under my notice, the distal end was broken 

 from the shaft ; and the shaft was split, showing the very thin 

 condition of the bone of the shaft, and the hard, sandy, calcareous 

 matter which filled the medullary cavity. Traces of matrix at the 

 distal end show that the specimen has been derived from quartz- 

 sand bound together with limonite, such as might occur in the 

 Hastings Sand, Weald Clay, or Lower Greensand, but the character 

 of this matrix is opposed to the possibility of the specimen being of 

 post-Tertiary age. 



The fossil, as preserved, is 4 inches long, and indicates a humerus 

 which may have been 6 inches long when perfect, as large as that 

 of a wolf, but smaller than in a bloodhound. 



The shaft of the bone is flattened on the inner side^ convex on the 

 outer side, and thus it has a side-to-side compression approximating 

 to half a cylinder, but is somewhat flattened towards the olecranon- 

 pit behind. It is rather obliquely flattened above the condyles 

 in front, making the shaft | inch deep on the inner side at the 

 distal end, and rather less on the outer side. The side-to-side 

 measurement is least, as usual, above the distal articulation. Towards 

 the proximal fracture the depth of the shaft, which is augmenting,, 

 is y^Q- inch from front to back, while the side-to-side measurement 

 is -f^ inch. 



The form of the shaft, flattened on the inner side, precludes any 

 comparison of the animal with Carnivora, and indicates a resem- 

 blance to Ungulate types. 



The distal articular condyles are set on to the shaft at a forward 

 angle, which shows the animal to be terrestrial. When the shaft is 

 held vertically, the condyles are anterior to it. There is no animal 

 known to me in which this character is developed to the same extent. 



The extreme width of the condylar end of the bone is 1| inch. 

 In narrowness of the condyles the character is somewhat pig-like. 

 I'he external surface of the condylar end of the bone is convex and 



