HATCHER: OSTEOLOGY OF HAPLOCANTHOSAURUS 5) 
positions relative to one another. While aided by diagrams of the quarry, repro- 
duced here in Figs. 1 and 2, and the proper marking of each block as it was taken 
up, it is now easily possible to assign the different blocks to their proper position in 
the quarry and thus to determine with accuracy the relative positions of all the 
different bones as they lay imbedded in the rock. 
In the laboratory the bones have been very carefully and skillfully freed from 
the matrix under the direction of Mr. Arthur $. Coggeshall as Chief Preparator 
assisted by Messrs. W. H. Utterback, L. S. Coggeshall and A. W. VanKirk. 
When freed from the matrix the bones were all faithfully drawn by Mr Sydney 
Prentice, draughtsman in the Paleontological Department of this Museum. 
The type No. 572 of the present genus consists of the two posterior cervicals, 
ten dorsals, five sacrals, nineteen caudals, both ilia, ischia and pubes, two chevrons, 
a femur and a nearly complete series of ribs, all in an excellent state of preservation 
and pertaining to an individual fully adult as is shown by the codssified neural 
spines and centra. 
Posrrion oF THE DirrErENT Bonks As THEY Lay IMBEDDED IN THE QUARRY. 
The pelvis, sacrum, left femur and nineteen anterior caudals were the first por- 
tions of the skeleton discovered. They lay in the position shown at A. 572 in the 
diagrams of the quarry shown in Figs. 1 and 2. The ilia, ischia and pubes still oc- 
cupied approximately their normal positions relative to the sacrum, and the femur 
was directed backward and downward, with the head removed about two feet from 
the acetabulum. The anterior caudal was displaced from its normal position rela- 
tive to the distal extremity of the sacrum, but the succeeding eighteen caudals were 
interlocked by their zygapophyses. ‘The two chevrons lay as shown in the diagram, 
approximately in position, with caudals eight and thirteen. I personally assisted 
in taking up this portion of the skeleton and am therefore somewhat familiar with 
its appearance as it lay in the quarry. 
At a distance of about twelve feet but on the same level as the pelvis and bones 
above mentioned, were found the nine posterior dorsal vertebree shown at B. 572 in 
the diagrams of the quarry. These were all interlocked by the zygapophyses and most 
of the ribs were still in place. The last of this series agrees very well in size and 
general appearance with the first sacral of the series found at A. 572, and there would 
seem no good reason for assuming that the two series pertain to other than one and 
the same skeleton, though, of course, this cannot be absolutely demonstrated, but 
the characters exhibited by the two series demonstrate that they pertain to the same 
species at least and I have little doubt but that they belong to the same individual. 
