SCO ON THE FOSSIL B0NE9 OF PACHYDERiWATOUS QUADRUPEDS. 



Its greatest length, from the extremity of its posterior tuberosity to 

 the upper edge of the cuboidian facette, is 0,19. 



Its greatest height, from the summit of the facette joining the fibula, 

 to the inferior tuberosity, is 0,11. 



This height corresponds almost exactly with that of an elephant 

 eight feet in height. 



3rd. A large bone of the carpus, mutilated but distinguishable. It 

 is similar to the corresponding part of the elephant, but it is narrower 

 in proportion. Its lower lateral facette for the index, is also a little 

 larger in front. It is 0.06 in height, 0,07 broad, and 0,08 in anterio- 

 posterior diameter. Some rather large fragments of ivory were found 

 in the same bed — a circumstance tending to prove that the narrow- 

 toothed mastodon had tusks. 



But a more decided proof of this is afforded by a discovery made in 

 the department des Hautes Pyrenees, at Sariac, in the canton of Cas- 

 telnau, in the valley of the Gers ; and in a marl pit, 24 feet deep, 

 situated at a quarter of a mile from the river. 



M. Lourtau, a young physician of that country, has sent me the 

 most interesting specimens found in that quarter ; they consist of 

 three entire grinders, two fragments of grinders, and several sections of 

 tusks, large and small. 



The two first jaw teeth have the usual four pair of lobed denticuli, 

 and a little fang. The two points of the anterior pair are much worn, 

 and present us with irregular trefoil figures. 



One of those of the second pair is also somewhat worn, the remain- 

 der are entire. The crown of these teeth is 0,14 long, and 0,075 

 broad in front. The enamel is precise^ similar in every respect to 

 that of the tooth of Simorre. It is of a blueish white in many places, 

 shaded with a reddish hue. 



The third is attached to a section of ivory, quite altered and incrust- 

 ed with a sort of stalactite crust, 0,27 in length. It is ^pointed and 

 compressed ; its section is 0,7 in its greatest diameter, and 0,5 in its 

 smallest, but it joins other sections, with" which it forms a tusk at least 

 0,86 in length, with a diameter at the base of 0,13. There are other 

 fragments also corresponding with each other,and forming atusk of more 

 than a metre in length, with a diameter of 0, 13 at the base. The two 

 last specimens unite and form a section 0,52 long, with the same di- 

 ameter as the others. These three portions of tusks appear to have 

 been almost straight. The ivory is very much altered ; the incrusta- 

 tion which has formed upon it, and which has even penetrated into the 

 interstices of its plates, is of a greenish grey, intermixed with numer- 

 ous hard sharp plates. 



But the most important fragment is a section somewhat arched, 0,14 

 long, and though broken at both ends, its thickness is not sensibly di- 

 minished. It must have formed part of a long tusk, which must un- 

 doubtedly have projected from the mouth, and yet it is enveloped in a 

 coat of real and very hard enamel, not at all so tender as the crusts of 

 the tusks of the elephant. 



The outline of this fragment of a tusk is a very regular oval, mea- 

 suring 0,065 in its greatest diameter, and 0,05 in its smallest. 



The process of decomposition has divided its layers into concentric 



