75 



Iliac facet small, separated from the ischiac facet by a wide, concave, acetabular emargi- 

 nation that forms about oue-third of the whole acetabular border. 



Measurements of pubis. 



M. 



Length of acetabulcar border along curve ...... '235 



Distance from centre of ischiac facet to centre of iliac facet ■ 205 



Breadth at narrowest part of anterior expansion .... "092 



Thickness at centre of narrowest part '027 



Breadth of specimen anteriorly (imperfect) '174 



Circumference of base of postpubic process .... • 092 



Vertical diameter of ischiac facet , • 045 



Greatest thickness slightly in advance of acetabular border -022 



Greatest thickness at centre of anterior end (imperfect) of specimen. 018 



Length of specimen from ischiac facet to anterior end ■ 485 



Estimated length of pubis, when perfect, from anterior end to posterior end of 



postpubic process (37 inches) ■ 940 



Ischium long, plate X, fig. 2 (provisionally associated with T. marginalus), laterally 

 compressed, broadly expanded proximally and ending distally in a foot-shaped extre- 

 mity pointing downward. Shaft almost straight, its upper edge curving concavely and 

 broadly upward to meet the iliac facet. Upper expanded part very thin, plate-like, 

 thickened abruptly, on either side of the thin, concave edge of the acetabular border, to 

 form well developed iliac and pubic facets. The surfaces of the facets very rugose. A 

 narrow postpubic facet extends, downward and backward at right angles to the pubic 

 facet along the lower front border of the proximal end. Below this facet and separated 

 from it by a concavity in the thin margin is a flange of bone for the further support of 

 the postpubis. Inner surface of distal half, striated longitudinally for a ligamental 

 union with its mate of the opposite side. 



Measurements of ischium. 



M. 



Extreme length from iliac facet 1 ■ 050 



Distance from upper end of iliac facet to lower end of pubic facet • 332 



Length of acetabular border measured on concavity 140 



Length of iliac facet 135 



Breadth of same • 060 



Length of pubic facet • 040 



Breadth of same • 020 



Length of postpubic facet. -122 



Breadth of same ,. 013 



Circumference at mid-length 162 



Breadth of expanded distal end. , '0217 



Thickness of lower part of same • 070 



Thickness of upper part of same , • 040 



Thickness of proximal expansion at centre 016 



A number of ilia, representing different types of herbivorous dinosaurs, are included 

 in the collections. In fig. 23, three of these are shown. The irpper one. A, is of the 

 Monoclonius type and is arbitrarily associated with M. dawsoni, another, B, is referred to 



