DECEMBER 15, 1899. ] 
had cut through a small section of the 
caudals. In front of the sacrum the 
dorsals stretched forward in a promising 
way, but the centra were wanting, and 
finally nothing but the neural arches re- 
mained. The left side was found most 
deeply imbedded and most completely pre- 
served in the region of the sacrum. The 
~ bones recovered, with the exception of 
three cervical vertebree and the complete 
right seapula, are shown in the accompany- 
ing restoration. Not only the relative com- 
pleteness of this skeleton, but the highly 
skillful manner in which it was taken out, 
render it unique. Upon arrival in the 
Museum, the reconstruction of the pelvis 
and sacrum proved especially difficult, but 
was completed successfully. 
The points of greatest novelty are found 
in the vertebral column, since the only por- 
tions of this region described by the late 
Professor O. C. Marsh are a single cervical, 
an anterior dorsal, three sacral centra, and 
one caudal with chevrons. In order to un- 
derstand the general structure of the pos- 
terior half of the column, that is from the 
8th presacral backwards, the reader is re- 
ferred to the restoration, Fig. 1. A re- 
markable balance between the opisthocelous pre- 
sacrals and proccelous postsacrals is observed. 
Vertebra for vertebra they correspond very 
nearly in size, with a slight advantage in 
favor of the presacrals. The balance was 
completed by the ponderous tail stretching 
out to a length of 30 feet. Between these 
balanced dorsals and caudals are the exces- 
sively rigid sacrals, coalesced with each 
other and with the ilium. Thus a long 
balanced vertebral lever is established with 
the acetabulum as a fulcrum, with opis- 
thoccelous vertebre in front and proccelous 
vertebree behind. The dominating principle 
in construction of the backbone is maxi- 
mum strength with minimum weight. The 
ingenuity of sculpture by which this is 
brought about, every single vertebra differ- 
SCIENCE. 
871 
ing from its fellow, baffles the Lamarckian 
as well as the Darwinian, and tempts us to 
revive the old teleological explanation. 
The neural spines, arches and centra are 
constructed in such a manner as to connect 
all the principal points of stress and strain, 
and at the same time reduce the weight to 
the last degree. They are proportioned in 
each vertebra to meet its peculiar condi- 
tions, no two vertebre being alike. 
Presacrals 2 and 1 are of great interest 
because, as in the Struthious birds, the ribs 
they bear lie behind the ilium, the 14th 
being still free, the 15th having coalesced 
with the ilium. Theanalogy with Apteryx 
is very striking. 
The three anterior sacrals, constituting the 
primitive Dinosaur sacrum, are firmly 
united together by their neural spines. 
These spines coalesce into a single very 
robust spine, showing the diapophysial 
lamin separate ; the antero-posterior di- 
ameter of this spine is far less than that of 
the three coalesced spines of Brontosawrus or 
Morosaurus. 
The sacrum of Sauropoda is reinforced 
by the addition not of dorsals, but of an- 
terior caudals. The third sacral was prob- 
ably the first of the anterior caudals to be 
added in an ancestral stage of evolution. 
The fourth sacral is still more conspicuously 
a modified caudal. 
This is the first instance among the 
Sauropoda in which a nearly complete sac- 
rum has been found attached to the ilium. 
This fortunate circumstance determines the 
correct position of the ilium with relation to the 
sacrum, and shows that the entire pelvic 
girdle has been incorrectly placed hitherto ; 
Marsh’s error consisted in his placing the 
anterior and posterior acetabular borders, 
or pubic and ischiac peduncles, of the ilium 
upon the same horizontal plane, thus di- 
recting the superior iliac crest backwards ; 
and altering the natural angle of the entire 
pelvis. The second point of great interest 
