72 BRITISH AND EUROrEAN FOSSIL MASTODONS. 



trenchant ridges, a basal inner bourrelet, and a front and back talon 

 developed like the bourrelet. Each ridge consists of about six points. 

 This is evidently the vertical premolar succeeding the last milk molar, 

 as it shows no disc of pressure either in front or behind. 



Length of crown including talons, 1*8 in. Width of crown at front ridge, 

 1-3 in. Width at second ridge, V5 in. 



The tooth is partly embedded ; the width of the trenchant edges is 

 nearly as great as of the base. 



In front of this there is an obscure appearance of another minutely 

 cusped tooth, probably another premolar ! in which case it would be the 

 successor of the second milk molar. But the mass is too conglomerated 

 to make this certain. There had evidently been a tusk along the side 

 which has left its grooved impression. 



8th. Another beautiful small conglomerated fragment consists of: 

 1st, a portion of grooved tusk distinctly showing guilloche; 2nd, a square 

 two-ridged tooth exactly the counterpart of the last, and also in germ ; 

 and 3rd, a small two-fanged oval crowned complex germ tooth, exactly 

 like that described as being the vertical premolar of Mast, angustidens ; 

 but dislocated and at right angles to the other tooth. 



Length of two-ridged tooth, 1*8 in. Width at front ridge, 1*4 in. Width at 

 back ridge, 1-55 in. 



In every respect, in size, in form of ridges (which are not parallel 

 in either), it is exactly like the other, and probably of the opposite 

 side. 



The small tooth in the first specimen would therefore seem not to be 

 of Mast, angustidens, but of M. Borsoni. 



The grooved tusks would also seem to be of this species. 



All these fragments are marked on the labels as being from Elgg, but 

 this is denied by Mons. Escher. 



9th. Examined a beautiful germ-specimen of the penultimate of lower 

 jaw, left side, with a disc of pressure in front, but cmite unworn. The 

 ridges very trenchant; a vertical keel to the inner tubercle of front 

 ridge ; the ridges sloping a little backwards and outwards. No inter- 

 ruption to valleys ; outer and inner points most elevated ; middle points 

 concave; posterior talon transverse, consisting of small crenulated points; 

 anterior talon very little developed ; no basal bourrelet ; and no constric- 

 tion as in Mast, angustidens. 



Length of crown, 4 - l in. Width at 1st ridge, 2 - 25 in Width at 2nd ridge, 

 2-55 in. Width at 3rd ridge, 275 in. 



I infer this to be the penultimate of Mastodon Borsoni, but the 

 position is not absolutely determined. 



In all these specimens, a little connecting keel descends from the 

 anterior and posterior sides into the valleys without in the least in- 

 terrupting them ; from the inner points (outer Lartet) of the upper 

 teeth, and outer points (inner) of the lower ; being a very reduced 

 condition of the bridge seen in Kaup's Mastodon longirostris ; it is 

 very minutely crenulated, forming a keel. There is also a marginal 

 crest to the outer of upper, and inner of lower, but less marginal in the 

 upper. 



10th. Another specimen, containing the third milk molar (anterior 

 ridge broken off) of the lower jaw, presents the same characters. It has 



