64 THE DESEADO FORMATION OF PATAGONIA 
TI . e 
= rr, upper inc. 2 and 3 and lower inc. 
3 vestigal, upper pms. not molariform, molars with a deep 
internal fold. 
Propachyrucos, 37q3, lower jaw only, similar to Pa- 
chyrukhos but have inc. 3, the canine, and pm. 1 present 
and only a little reduced. 
Phanophilus, upper molars only, but peculiar in having 
a strong external medial column. 
Prosotherium, 
Prohegetotherium Ameghino 
Prohegetotherium Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 424. 
This little known genus is characterized by the upper 
molars having an external furrow near the anterior margin 
of the tooth. Otherwise it is similar to Hegetotherium. 
Ameghino described a species where the external surface 
of the bones was sculptured ‘“‘like reptiles.”’ I do not see 
how, with the arrangement of the muscles usual to mam- 
mals, the sculpture could be similar to that of reptiles, and 
feel that this is due to conditions of weathering. We did 
not find this species, but did find a form which resembled 
it in general, but differed in being smaller and with the 
external furrow less developed. 
Prohegetotherium sculptum Ameghino 
P. sculptum Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 424. 
This species is characterized by the deep external fur- 
row on the upper molars. The measure given is 34 mm. 
for the length of the three upper molars. 
Prohegetotherium shumwayi sp. nov. 
Founded on a portion of the right maxilla, carrying pm. 
2 to 4 and m. 1, found on the Chico del 
Chubut, west of Puerto Visser, by Waldo 
Shumway. 
The teeth are simple, with but a shallow 
external furrow near the anterior margin of the premolars 
Fig. 29. H. Shumwayi 
—natural size. 
