260 IR (CM (OASIS 
remain and enough of the edges to make the restoration here 
given fairly accurate. The three bones meet in the center of a 
wide and rather shallow cotyloid cavity with a very prominent 
inferior-posterior lip projecting from the ischial portion. The 
illum is rather blunt anteriorly and tapers posteriorly, the 
inferior edge is thicker and rather rod-like and the upper 
portion is thinner and more plate-like. Attached by the iron 
cement to the inner side of the ilium are the distal ends of three 
sacral ribs, the anterior shows the same characters as figured in 
the solitary sacral vertebra described above. The anterior 
upper edge of the pelvis, formed by the adjacent portions of 
the ilium and pubis is rather rugose. The pubis is rather elon- 
gate, the upper edge is thicker and the lower thinner and plate- 
like. The ischium has a very thick acetabular portion which 
forms a prominent lip as described ; the rest of the bone is very 
thin and is rather rounded in outline. Closely cemented to the 
inner face of the ischium figured is the lower portion of the 
same bone of the opposite side. This ischium differs quite 
markedly from another in the same collection which is much 
more elongate and slender. 
It is peculiarly unfortunate that a specimen which is so 
completely preserved should be preserved in a cement so hard 
that it is only by the sacrifice of the superficial layer of the 
bone that it can be removed. Any attempt to remove the 
cement is an almost hopeless task as it strikes sparks from the 
chisel; however, enough has been made out to show that it 
contains a nearly perfect half of the skull, the majority of the 
vertebral column, most of the limb bones, and a nearly perfect 
anterior foot, all of which the author hopes to describe and 
figure at an early date. 
E: €. Case: 
STATE NORMAL SCHOOL, 
Milwaukee. 
EXPLANATION OF PLATES I AND II. 
Fic. 1.—Series of vertebre from the middle portion of the column of Lysorophus 
tricarinatus. One-half natural size. 
