72 SCOTT. [Vol. V. 



confirms the position reached in the article cited ; viz. that all 

 the great groups of selenodont artiodactyls when traced back 

 are seen to arise independently from the abundant and wide- 

 spread Eocene type, which may be called the Buno-Selenodonta; 

 and which forms, as it were, a lake from which several streams, 

 flowing partly in parallel, partly in diverging directions, are 

 derived. It seems very clear that the term "selenodont," 

 though most useful as a descriptive word, has no value as a 

 term of classification. 



In the discussion of the structure and succession of the 

 Tylopoda, I have merely endeavored to establish the facts, 

 reserving for the second paper all attempts at explaining those 

 facts ; for such explanation will be rendered easier by the study 

 of some other lines of mammalian descent, and by the compari- 

 son of the facts thus obtained with those which the history of 

 the camels offers for our consideration. 



LIST OF PAPERS CITED. 



(i) Baur, G. — Das Trapezium der Cameliden. — Morphologisches Jahr- 

 buch. Bd. XI. 



(2) Boas, J. E. V. — Zur Morphologie des Magens der Cameliden und der 

 Traguliden. — Ibid. Bd. XVI . 



(3) Ueber den Metatarsus der Wiederkauer. — Ibid. 



(4) Branco, W. — Ueber eine fossile Saugethierfauna von Punin bei 

 Riobamba in Ecuador. Palaeontologische Abhandlungen von Dames und 

 Kayser. Bd. I. Heft 2. 



(5) Bruce, A. T. — Observations on the Brain-Casts of Tertiary Mammals. 



— Bulletin E. M. Museum of Geology, Princeton. No. 3. 



(6) Cope, E. D. — Report upon Extinct Vertebrata obtained in New Mexico, 

 etc. — Geograph. Surveys West of the 100th Meridian. Vol. IV. Part II. 



(7) Tertiary Vertebrata. — Report U.S. Geol. and Geogr. Survey of 



the Territories. Vol. III. 



(8) On the Structure of the Feet in the Extinct Artiodactyls of North 



America. — Proc. A?ner. Ass. Adv. Science. 1884. 



(9) The Phylogeny of the Camelidae. — American Naturalist. Vol. 



XX. 



(10) Flower, W. H. — On the Value of the Characters of the Cranium in 

 the Classification of the Order Carnivora, etc. — Proc. Zool. Soc. London, 

 1869. 



(11) Furbringer, M. — Zur Lehre von der Umbildung der Nervenplexus. 



— Morphologisches Jahrbuch. Bd. V. 



