4 PROCEEDINGS OF THE NATIONAL. MUSEUM vol. 66 



4. On the relation of the Texan mastodon to the South American species 



Boiile and Thevenin ^ have shown how difficult it is in many cases 

 to identify isolated teeth of the two recognized species of South 

 American mastodons. They have demonstrated, furthermore, that 

 the skulls and the tusks of the two species are wholly different. Now, 

 in the case of the animal which bore such teeth as those represented 

 by the Cameron specimen and the one in the British Museum, we 

 know nothing about the skull or even the tusks. However much 

 the teeth may resemble those of M. humholdtii or M. cordillenim^ 

 the upper tusks may have been straight or curved or twisted, or 

 spiral, with or without an enamel band. The skull may have been 

 in a stage of development like that of M. aThdiutn or in one like 

 that of M. huTriboldtii; or it may have been in an intermediate stage. 



Furthermore, it is uncertain that there is a single species of 

 North American fossil vertebrate which is identical with a South 

 American form. There is finally another reason why the Texas 

 mastodon should not be referred to either of the species belonging 

 in South America. This is found in the greater height of the crowns 

 of the teeth. The height of the outer column of the third crest of 

 the British Museum specimen, measured from the lower edge of 

 the enamel to the summit, is 93 mm. The height of the corre- 

 sponding column of the tooth in the lower jaw No. 19951 of the 

 British Museum as represented by the cast mentioned above, is only 

 76 mm. 



In the United States National Museum is the cast of another 

 tooth belonging to the British Museum and recorded by Lydekker ^ 

 by the number 19952e, and referred to M. humboldtii. This tooth 

 is the lower right third molar and is 200 mm. long. In this, due 

 allowance being made for the slight wear, the height of the column 

 measured in the other specimens is little more if any than 60 mm. 

 It appears evident, therefore, that the Texas tooth is more hyp- 

 sodont than those of the South American species. 



5. On the status of the generic namh anancus 



For certain species of mastodons, including the one described 

 above, the writer employs the generic name Anancus. This was 

 first used for mastodon remains b}^ Aymard in 1854," when he an- 

 nounced a supposed, new species Ariancus macroplus ; but he gave no 

 description of either the genus or the species. Falconer ^ cited page 

 276 of the Congres Sclentiflque de France, 1855, for the name. 



* Mammiffires foss. de Tarija, 1920, pp. 44, 63, 64. 



8 Cat. Foss. Mamm. Brit. Mus., pt. 4, p. 44. 



" Ann. Soc. Agric. Sci. le Puy, p. 597. 



' Palaeont. Menioir.s, vol. 2, p. 20, footnote. 



