154 THE DESEADO FORMATION OF PATAGONIA 
found no specimens of this species. The following are 
the measurements of the type according to Ameghino. 
Lower dentition, molar 1, length 3I mm., width 16 mm. 
Lower dentition, molar 2, length 42 mm., width 21 mm. 
Parastrapotherium martiale Ameghino: 
P. martiale Amegh., 1901, Bol. Acad. Nac. Cordoba, t. 16, p. 402. 
P. superablie Amegh., 1901, Bol. Acad. Nac. Cordoba, t. 16, p. 402. 
The species seems to have been founded on abundant 
material, representing an animal of larger size than P. 
holmbergi, which 1s dis- 
tinguished by the 
greater width of the 
crowns of the incisors, 
by straight canines 
diverging but little, by 
a strong cingulum on 
the outer side of the 
lower molars and the 
inner side of the upper 
molars, and by the 
narrow symphysis of 
Fig. 108. Upper molar 1 of the left side—natural size, 
atten ucenino: the lower jaws. P 
superabile was distinguished by a difference in the arrange- 
ment of the roots of upper pm. 4, but as the pattern of the 
crown is the same, as is also the size, I feel that this differ- 
ence is simply an individual variation. The following 
measurements are given by Ameghino: 
Upper dentition, length from pm. 3 to m. 3 240 mm. 
Upper dentition, premolar 4, length 30 mm. 
Upper dentition, premolar 4, width 43 mm. 
Upper dentition, molar 2, length 82 mm. 
Upper dentition, molar 2, width 83 mm. 
Lower dentition, length from inc. I to m. 3 550 mm. 
