34 
PATAGONIAN EXPEDITIONS : PALEONTOLOGY. 
Patriarchus altus Amegh.; Revista Argent, de Hist. Nat., I, p. 293, 1891. 
Protypotherium altum Amegh.; Enum. Syn., p. 13, 1894. 
? Proty pot herium lineare Amegh.; Enum. Syn., etc., pp. 13-14, 1894. 
This is the largest and also the most abundant species of Protypotherium 
in the Santa Cruz beds. It may be readily recognized by its large size 
(skull length .099-. 1 12). There is considerable individual variation in the 
size of the skull and teeth, but with a sufficiently large suite of specimens 
it is possible to detect all transitions between the extremes in dental and 
cranial measurements. 
Specimens in the Munich collection, determined by Ameghino as Patri- 
archus palmidens and P. furculosus , are old individuals of P. australe. The 
latter differs from P. prcerutilum, a smaller and more slenderly constructed 
form, in the greater width of the molar crowns, which, although they may 
in some of the smaller individuals approach those of P. prcerutilum in 
antero-posterior diameter, are always much wider. 
From P. attenuatum the species under consideration differs in its much 
greater size and in the less pronounced dilatation of the parietal region of 
the skull. 
The specimens selected for measurement and illustration represent 
fairly well the extremes of size variation within the limits of the species. 
Nos. 15,828, 15,340, 15,551, 15,598 of the Princeton collection, and Nos. 
9565, 9149 and 9566 of the American Museum collection, are figured on 
the accompanying plates. 
The following localities are represented, the figures referring to the 
number of individuals from each: Rio Gallegos (3), Canon de las Vacas 
(2), Felton’s estancia, Rio Gallegos (7), Halliday’s estancia, Rio Gallegos 
(4), Killik Aike (7), West of Killik Aike Ranch, Rio Gallegos (1), two 
miles west of Killik Aike, Rio Gallegos (1), five miles south of Coy Inlet 
(1), ten miles south of Coy Inlet (1), seventeen miles north of Cape Fair- 
weather (1), Mount of Observation (2). 
Measurements. 
No. 
No. 
No. 
No. 
13,828. 
9565 - 
1 5 , 39 s ■ 
914.9. 
Skull, 
maximum length .... 
.112 
.108 
n 
length, premaxillae to condyle inclusive 
.1085 
•1055 
.099 
u 
greatest width across arches . 
.0645 
.061 
.062 
u 
interorbital width 
.032 
.031 
.0273 
