q 
i 
104 MEMOIRS OF THE CARNEGIE MUSEUM 
a corresponding surface on the anterior face of the pleurapophysis of the first sacral 
vertebra and is somewhat similar to what is found in Hippopotamus. The trans- 
verse process of the last lumbar vertebra in Archxotheriwm is otherwise quite light, 
as is the case in all the preceding lumbar vertebric. In the specimen under descrip- 
tion the heavy posterior border of the transverse process of the vertebra does not 
come in contact with the anterior face of the pleurapophysis of the first sacral, but 
had a cartilaginous attachment with the ilium. The neural spine has a vertical 
position and its anterior and posterior borders gradually taper from the base of the 
spine to the summit. The latter is rounded, slightly enlarged, and rugose. The 
neural canal is broad, but low, and its floor is occupied in the median line by a 
heavy ridge, which extends antero-posteriorly the entire length of the superior face 
of the centrum. The centrum is depressed, but possesses a considerable transverse 
diameter ; its posterior face is larger than its anterior. The prezygapophyses have 
prominent surfaces for the episphenial processes of the vertebra in advance of it, and 
these processes of the postzygapophyses are also quite prominent. 
Sacrum. —'The sacrum is composed of three well coéssified vertebra. The 
centrum of the first sacral vertebra is quite large, but the succeeding two rapidly 
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Fia. 60. Inferior and Superior Views of Sacrum of D. hollandi Peterson. 4% nat. size. (Carn. Mus. Cat. 
Vert. Foss., No. 2126.) 
decrease in size, so that the posterior face of the centrum of the last vertebra has 
the transverse diameter less than one half of the anterior face of the first sacral. 
The pleurapophyses, which are very heavy on the first sacral, decrease in the 
posterior sacrals as rapidly as the centra. Unfortunately the neural spines are lost, 
“In examining the sacrum of the Princeton specimen, Archwxotherium ingens, No. 10885, it is seen that on its ven- 
tral face there are three distinct centra, which are very firmly codssified. Professor Scott (87, p. 294) mistook the two 
posterior centra of this sacrum for one only. 
