178 THE DESEADO FORMATION OF PATAGONIA 
and slow-growing animal. Most all of the material found 
by any of the collectors falls clearly into this species. 
Our specimens all came from the Chico del Chubut, west 
of Puerto Visser, which point is about 250 miles north of 
the locality where Gaudry’s material was found. 
The general features of the skull have been given under 
the generic description. The difference between this 
and the preceding species lies in the absence of pm. 1, 
and the somewhat larger size. Both of our major speci- 
mens are mutilated in places; and as the better skull was 
found with only the zygomatic arch exposed, we conclude 
that the parts missing were lost before burial. On the 
lower jaw the edges of some of the teeth were cracked off, 
and both the ascending rami are lacking, both things having 
happened before burial, this specimen being found well 
in the bank and never exposed to weathering. It appears 
as if the carcasses of the animals lay some time before 
being buried by the sediments. The scattered condition 
of all the finds indicates the same thing. The head of 
our femur is still marked by the teeth which cleaned the 
meat from the bone. The frequency of isolated tushes 
indicates that many jaws originally containing them have 
been either chewed to pieces or weathered away before 
burial. I do not think all the tushes found originally 
belonged to the lower jaw (Gaudry reports 18 tushes, all 
lower); for the upper and lower tushes when isolated are 
so much alike that it is difficult to distinguish them. 
The size of the skull isindicated by the following measure- 
ments: SPECIMEN No. 3207 
Length from inc. 1 to occipital condyles 720 mm. 
Length from front of premax. to nasal opening 225 mm. 
Length of boss on premaxilla 77 mm. 
Length of nasal opening at top 80 mm, 
Width of nasal opening at top 88 mm. 
Length from premax. to lambdoidal crest 540 mm, 
Width across zygomatic arches 350 mm, 
Width across frontal bones go mm, 
Transverse diameter of the snout 115 mm, 
