1857.] FALCONER' — MASTODON. 341 



species. But the symphysis, instead of being elongated into a pro- 

 cess composed of the alveoH of two mandibular incisors, terminates 

 suddenly in a short beak, as in the Elephants and other Probosci- 

 dean species that are destitute of inferior tusks. This beak does 

 not project much more beyond the anterior rounded surface of the 

 jaw than in the African Elephant, or in M. {Trilophodon) Hum' 

 boldtii, also a species without mandibular incisors ; but it differs from 

 them and all other known species in the diastemal ridges expand- 

 ing at the point, so as to form a short, blunt, dilated spout. This cha- 

 racter is well shown by the Val d' Arno specimen delineated by Cuvier 

 in the * Ossemens Fossiles, ' tom. i. t. 9. f. 5 & 6, after Nesti. It is 

 one of the pieces upon which Nesti founded his Elephas meridionalis ; 

 but which, although the molars are wanting, Cuvier sagaciously in- 

 ferred, from the general form, to belong to a Mastodon. I was en- 

 abled, by the obliging permission of Professor Gaspero Mazzi, to 

 examine the specimen minutely, and to compare it with the nume- 

 rous lower jaws of -E'. (Loxodon) meridionalis and of M. (Tetralopk,) 

 Ai'vernensis contained in the Natural History Museum at Florence, 

 and was satisfied that it belonged to the latter species, as Cuvier 

 had inferred from the drawing. The same Museum contains the 

 greater part of a skeleton of this Mastodon, found in a marine de- 

 posit of the lower Val d'Arno above Leghorn. The lower jaw of 

 this specimen presents the same character of a short symphysial 

 beak without incisors. The same is exhibited by the lower jaw of 

 the Dusino skeleton from the Astesan, described by Prof. Eugenio 

 Sismonda*. They all agree in the common characters, so far as 

 these are shown, of a Tetralophodon-iovvavXdi to the crown-ridges of 

 the three molars here called intermediate ; of alternate mammillae 

 to the ridges, with blocked-up valleys ; and of a short obtuse beak 

 with no incisors. 



Sismonda describes and figures the lower jaw of the Dusino spe- 

 cimen as being without tusks, or remains of their sockets. But, pre- 

 disposed to believe that they must have been present at some period 

 of the animal's existence, from their occurrence in other Mastodons, 

 he conjectures that those tusks had fallen out early, and that the 

 alveoli had been obliterated by filling up ; and he has given a re- 

 presentation of a very mutilated fragment of a Proboscidean sym- 

 physis of the lower jaw, as exhibiting the alveoli of two mandibular 

 incisors f . I was enabled, by the obliging kindness of Signor Bar- 

 tolomeo Gastaldi of Turin, to examine the specimen in question, 

 which is very much rolled, and in a different mineral condition 

 from the fossils of the Dusino Mastodon-bed, and found that the 

 supposed incisive alveoli were only the anterior terminations of 

 the dentary canals, which are of large size in all the Proboscidea. 

 The form impressed me with the conviction that it was more pro- 

 bably the symphysis of an Elephant than of a Mastodon. This case, 

 therefore, gives no support to the belief that M. {Tetralophodon) 

 Arvernensis had lower incisors. 



* Osteograph. di un Mastod. angustidente, tab. 1. fig. 1. 

 t Op. cit.tdh. 1. fig. 7. ' 



2b2 



