324 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [April 8, 



made by M. Lartet, of the first announced fossil monkey in Europe, 

 of Macrotherium, Anisodon, &c. Among others, a vast quantity 

 of Mastodon-remains have been met with, including the whole den- 

 tition, from the young sucking-calf up to the adult and old animals. 

 A superb skeleton was disinterred by Laurillard at Seissan, so com- 

 plete in every respect, that it has been set up in the Paris Mu- 

 seum, alongside of the skeletons of the existing Indian and African 

 Elephants. Two points which have been invariably exhibited by all 

 these teeth are of special importance in their bearing upon the present 

 question ; the first is, that the intermediate molars are constantly 

 three-ridged, or, in other words, belong to the Trilojphodon type ; no 

 Tetralophodon molars having ever, within the knowledge of M. Lartet, 

 been discovered either at Simorre, Sansan, or Lombez : the second 

 is, that they entirely agree with the original Simorre types described 

 by Cuvier, upon which his M. angustidens is founded ; and that they 

 are absolutely the narrowest of all known Mastodon-molars. iVnother 

 remarkable character of the species is this, that, in harmony with the 

 narrow teeth, the horizontal ramus of the lower jaw is more com- 

 pressed, and higher in relation to the width, than in any other known 

 Mastodon. This is well shown in the Paris skeleton, and in nume- 

 rous lower jaws contained in the palseontological gallery. M. Lartet 

 possesses, in his rich collection at Seissan, several lower jaws exhibit- 

 ing the same character. A nearly entire skeleton of this species 

 was discovered in the latter part of 1855, in the sandstone-quarry of 

 Veltheim, near Winterthur in Canton Zurich ; this I was enabled 

 to examine minutely through the kindness of M. Ziegler-Ernst of 

 Winterthur. It is the largest specimen of the species that I have 

 anywhere seen. The lower jaw, although in fragments, is nearly 

 complete, and shows the extreme compression of the horizontal ramus, 

 and its great depth. I found, by measurement with the callipers, 

 that this compression was even greater than is seen in JDinotheriuniy 

 while the lower jaws of most of the known Mastodons and Elephants 

 yield more or less of a circular section. This tenuity of form is 

 carried on throughout the skeleton in the Mastodon of Simorre. 



From these remarks it would appear sufiiciently evident, that, 

 whether we are guided by priority of description and reference to the 

 original specimens, or by the obvious signification of the term, the 

 title of Mastodon angustidens is legitimately applicable to the Tri- 

 lophodon of Simorre, and to no other species : for it \^, par excellence, 

 the "Mastodonte a dents etroites" of Cuvier. The species, thus 

 limited, has nowhere been met with in the fossil state in England. 



{Mastodon Arvernensis and 31. longirostris.) — But Cuvier, as al- 

 ready stated, included under this name of M. angustidens other 

 remains which do not belong to it. Upon this head nearly all the 

 French palaeontologists are agreed, although at variance as to the 

 details. Of the specimens figured in the four plates devoted to 

 " Divers Mastodontes" in the 'Ossemens Fossiles,' all those from 

 South America, amounting to 10 in number, are by common con- 

 sent referred to one or two species peculiar to that country. Seven 

 are referable to the Mastodon of Simorre with narrow molars ; one 



