40 
PATAGONIAN EXPEDITIONS : PALAEONTOLOGY. 
Pes, digit IV, second phalanx, 
width proximally 
No. 
9 H 9 
.0066 
44 a a 44 44 
“ distally 
O 
O 
“ “ “ ungual “ 
length 
013 
a u 44 a 44 
width proximally 
005 
“ “ V, proximal “ 
length 
015 
n a a 44 a 
width proximally 
0065 
n a 44 44 
“ distally 
0045 
“ “ “ second “ 
length 
.0092 
a a u u 
width proximally 
■Ln 
O 
q 
44 44 44 44 44 
“ distally 
.004 
“ “ “ ungual “ 
length 
009 
44 44 44 44 44 
width proximally 
.004 
Protypotherium prcerutilum Ameghino. 
(PL V, Figs. 21, 22.) 
Protypotherium prcerutilum Amegh.; Enumeracion Sistematica, etc., p. 
15, 1887. 
Protypotherium compressidens Amegh.; Revista Argentina de Hist. Nat., 
I, p. 292, 1891. 
? Protypotherium convexidens Amegh.; Revista Argentina de Hist. Nat., 
I, p. 292, 1891. 
Patriarchus leptocephalus Amegh.; Revista Argentina de Hist. Nat., I, p. 
293, 1 89 1 ; Enum, Syn., etc., p. 14, 1894 (listed); Segundo Censo, 
etc., p. 150, 1898 (listed). 
Considerable hesitancy is felt in admitting this as a valid species. The 
only positive character of specific value seems to be the narrowness of 
the superior molars in proportion to their length. Although the length 
antero-posteriorly may be the same as in some of the smaller individuals 
of P. australe , the width is always less. The characters, apart from size, 
enumerated in the original descriptions (Ameghino, 1887, 15; 1889, 478) 
do not seem sufficient to warrant the separation of P. prcerutilum from 
P. australe. In the absence of exact stratigraphic data, the species as it 
stands now is a rather ill-defined assemblage of individuals intermediate 
in size between P. attenuatum and P. australe. Specimens in the Munich 
collection labelled by Ameghino P. leptocephalum are about the size of 
P. prcerutilum and might be grouped with the latter without overstepping 
the bounds of probability. Some do not differ greatly from medium sized 
individuals of P. australe. 
