268 BULLETIN 169, UNITED STATES NATIONAL MUSEUM 



The name Dinocerata was originally based on the uintatheres alone 

 and has always been taken as referring to them and including only 

 them,^^ so there can be no question as to the propriety of continuing 

 this name in this usage. 



What remains is to settle on a name for the Pantolambdidae and 

 Coryphodontidae. Some students (including me, 1931) have used 

 "Amblypoda" essentially in this sense, usually including the Perip- 

 tychidae. There is good precedent for such a restriction of a name to 

 one of several groups formerly included in it, and it is generally more 

 advisable than coining a new name. In the present case, however, it 

 should be avoided if possible. "Amblypoda" was based about equally 

 on the coryphodonts and the uintatheres. To exclude the uintatheres 

 from it is not quite the removal of the type group but certainly is a 

 radical change in usage and one not well justified. 



The name "Taligrada" might be expanded to this usage, but this 

 also is objectionable. As originally defined it was carefully drawn so 

 as to exclude and contrast with the best-known members of the group 

 for which a name is now sought, that is, the coryphodonts. Further- 

 more, in the past 40 years it has almost invariably been taken to 

 include or even to be typified by the periptychids. 



"Pantodonta" has none of these objections. It was proposed and 

 has always been used for typical members of the group now in question. 

 No animals foreign to this group have ever been called pantodonts. 

 Its original definition, although brief, offers a good contrast with both 

 Condylarthra and Dinocerata, even as those groups are now under- 

 stood, and would include the pantolambdids (not known when the 

 name wa's proposed), so that we are using the name exactly in the 

 sense of the original author, in fact more so than he did later. The 

 fact that a group that he later excluded from the Pantodonta is now 

 included seems to be of no particular importance, especially as his 

 original conception is not thereby changed. It is entirely proper in 

 taxonomy to extend a name formerly applied to one group to include 

 another later found to be closely related and is open to much less 

 question than would be the exclusion from a named group of a sub- 

 division on which it was originally largely based (as in excluding 

 uintatheres from the Amblypoda). The name "Amblypoda" I 

 would discard altogether, as not pertaining to any group acceptable 

 as natural or convenient in modern taxonomy. 



The present conception of the group Pantodonta may be summarized 

 as follows: 



" Marsh did suggest synonymy with Cope's broader "Amblypoda", but in fact nothing but the uinta* 

 theres was meant to be inchided in the original description and Marsh later (1S84) accepted this restriction, 

 for he proposed "Amblydactyla" to replace "Amblypoda" and to include both coryphodonts and uin- 

 tatheres, with only the latter listed as "Dinocerata." 



