PARASTRAPOTHERIUM 149 
of the pillar in the lower molars, which is a character 
due to youth; so I have considered it a synonym of P. 
holmbergi. P. ephebicum is a much smaller and distinct 
species, with which I should associate the single upper 
molar to which the name P. Jemoinet has been given. 
P. martiale is a large species, distinguished by the strong 
development of the cingulum on the internal side of the 
upper molars, and on the inner side of the lower molars; 
and by lower premolar 3 being well developed with two 
roots. P. superabile is of the same size as the foregoing, 
but has the cingulum on upper premolar 4 (the only tooth 
known) less developed. I should therefore consider it a 
synonym of P. martiale. P. insuperabile is the largest 
species, and is distinguished by the excessive development 
of the cingulum. JLzarthrus is founded on an upper pm. 4 
with a part of pm. 3, but, as far as I can see, does not differ 
in character or size from P. holmbergi. Traspoatherium 
is based on upper premolars which are distinguished by 
the roots being fused from side to side. I think it is an 
age character and for the present would consider it the 
same as P. holmbergi, probably the tooth being pm. 3. 
Parastrapotherium holmbergi Ameghino 
P. holmbergi Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 636. 
P. holmbergi Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 449. 
P. troussarti Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 638. 
P. troussarti Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 449. 
Liarthrus copei Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 641. 
Liarthrus copei Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 451. 
Traspoatherium convexidens Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 
O4!. 
Traspoatherium convexidens Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 
450. 
Parastrapotherium holmbergi Tournier, 1905, Bul. Soc. Geol. France, ser. 4, 
t. 5, p. 305. 
Astrapotherium holmbergi Gaudry, 1906, Anal. Palaeontologie, t. 1, p. 5. 
To this, the type species, I have assigned all the material 
we found on the Chico del Chubut, west of Puerto Visser, 
