HOLLAND AND PETERSON: OSTEOLOGY OF THE CHALICOTHEROIDEA. BAN 
Catalog No. 1705 (Moropus petersoni). 
This specimen consists of the two ossa innominata of an apparently mature 
individual, which, owing to the size of the pelvic aperture, the writer is inclined 
to regard as having belonged to a female, as he has stated previously (vide descrip- 
tion of M. petersont). 
Catalog No. 1793 (Moropus elatus). 
This consists of the right os Innominatum of a large individual presumably 
representing Moropus elatus. 
Catalog No. 1793A. 
This specimen consists of portions of the left innominate bone of a specimen of 
Moropus elatus somewhat smaller in size than No. 1793. 
Catalog No. 1794 (Moropus elatus). 
This consists of a fragment of the innominate bone, preserving the acetabulum, 
thyroid foramen, and the portions of the ilium, ischium, and pubis surrounding 
the acetabulum and the thyroid foramen. It represents an adult specimen of 
Moropus elatus. 
Catalog No. 1795 (Moropus peterson.), 
This bone has been already referred to and commented upon in the paragraph 
dealing with specimen No. 1701, to which it apparently belongs. 
In addition to this material there are a number of fragments which the writer 
does not deem it necessary to more than refer to. 
In all the material before the writer the ilium, ischium, and pubis are firmly 
coossified with each other, but not with the sacrum, which nevertheless in the 
case of specimen No. 1706 was found in situ lying between the ilia in such a manner 
as to show that when fully adult a firm union between the sacrum and the ilia was 
undoubtedly effected. It is evident that the union of the three bones which enter 
into the composition of the innominate bone took place, as in other mammalia, 
at a very early period, probably even during the feetal life of the animal. Few 
specimens have been found in which the sutures between the ilium, the ischium, 
and the pubis are visible. 
The tla are broadly expanded anteriorly, subtriangular in outline, the supra- 
iliac border rising high above the line of union with the sacrum, flaring upward 
and outward at the anterior extremity, thus giving this portion a somewhat scroll- 
shaped form, causing the gluteal surface to be deeply concave in front. ‘The 
bone between the broad expanded anterior portion and the acetabulum is lengthened 
