Progress in Mammalian Palaeontology.— Osborn. 223 
The Pliocene Fauna. 
Equivalent to Messinien (Pikermi), Plasancien (Cas- 
ino), Astein (Rousillon), Sicilien (Val d' Arno sup.) 
Our limited American Pliocene fauna still stands in sad 
contrast to the rich succession of Pliocene mammals of 
Europe. The Palo Duro mammals which Cope included in 
the Pliocene have proved to be Upper Miocene. Recent 
geological and palseontological work (G idley 3 ) shows that 
the only true Pliocene formation and locality is that of the 
Blanco beds of Texas, 75 feet in thickness, as against the 
rich successive Pliocene series of Europe. Nor are any 
species of Equus found here, as Cope supposed, and as 
might be expected from the presence of Equus (E. stenonis) 
in the Upper Pliocene of Europe. The chief faunal distinc- 
tions are the entire disappearance of the Rhinocerotidse and 
the appearance of South American Mammals. 
The zoogeographical changes are well known to enter a 
new relation by the invasion of the South American Edenta- 
ta, namely, Glyptodon, Megalonyx, Mylodon. Among these 
a new Glyptodont, Glyptotherium texanum has recently be- 
come known (Osborn 1 ) from a nearly complete carapace 
and partial skeleton, which exhibits primitive affinities with 
the Eocene types of Patagonia. Among the Proboscidea 
the Stegodont stage appears in the so-called Mastodon mir- 
ficus of Leidy, indicating a late Pliocene age for the Blanco 
formation. In the marine Miocene of Japan (Iwasaki and 
Yoshiwara 2 ) the remarkable discovery has been made of an 
anomalous skull representing a new family {Desmostylidae 
fam. nov.) either of hypsodont Sirenia or of Proboscidea, 
and Merriam 1 has recognized as a similar form occurring on 
the coast of California the genus Dexmostylus first noticed 
by Marsh. 
The phylogenetic series is all too limited, the horses 
2 A Horned Rodent. Bull. Amer. Mus. Nat. Hist., vol. xvi, 1902, pp. 
291-310. 
3 The Freshwater Tertiary' of Northwestern Texas. Bull. Amer. Mus. 
Nat. Hist., vol. xix, 1903, pp. 617-635. 
1 Glyptotherium texanum Bull. Amer. Mus. Nat. Hist., xix, 1903, 
pp. 491-494. 
2 Notes on a New Fossil Mammal. Jour. Coll. Of Sci. Imp. I'niv. 
Tokvo. vol. xvi, Art. 5, 1902. 
1 Science, n. s., vol. xvi. Oct. 31, 1902. p. 714. 
