700 



MH. J. W. HULKE ON" 



urally imitating the roof of a brain-case. The spaciousness of this 

 sacral expansion of the neural canal may be inferred from the di- 

 mensions of the best-preserved part of the roof, which are 16*5 centim. 

 longitudinally, and 8 centim. transversely. The transverse processes 

 of the sacral vertebrae are long, the second on the left side measures 

 24*3 centim. ; their vertical extent was considerable, their fractured 

 and mutilated lower border suggests their downward extension below 

 the neuro-central suture upon the lateral aspect of the centrum. 

 The number of sacral vertebras, inferred from that of the transverse 

 processes prolonged to the ilium, is four. Two in front of these I 

 am inclined to regard as lumbar, from the different direction and 

 length of the transverse processes. 



Ilia. — The ilium is remarkable for the great length of the prae- 

 acetabular process ; that of the left ilium (the better preserved) is 

 53 centim., the present entire length of the bone being 85*5 centim. 

 The breadth of the process taken just in front of the acetabulum is 

 18 centim., and at the distance of 15 centim. from its free anterior 

 extremity it is 15 centim. ; thus the borders of the process are almost 

 parallel. The acetabulum is capacious, the length of its chord 

 is 24*7 centim. The part lying above the acetabulum presents a stout 

 crest, which now projects externally beyond the outer lip of this 

 cavity, but which probably, before the bone was distorted by pressure, 

 was more erect. The longitudinal outline of this crest ascends for- 

 wards in a convex curve from the posterior extremity of the ilium 

 to above the middle of the acetabulum ; in front of this it descends, 

 becoming concave, and is lost upon the praeacetabular process. 



Vertebrce. — A caudal vertebra, well preserved, closely reproduces 

 in its general features those of Omosaurus armatus. The total height 

 of this vertebra from the apex of its spinous process to the lowest 

 part of the posterior articular surface is 38*1 centim. ; the height of 

 the spinous process and arch is 26*5 centim. ; the vertical diameter 

 of the anterior articular face is 11*2 centim., and the transverse 

 horizontal diameter 9*2 centim., the same diameters of the posterior 

 articular surface being 12*6 and 11-2 centim. ; and the antero-pos- 

 terior dimension or length of the centrum is 6-8 centim. Thus the 

 spinous process is lofty, the contour of the articular surface is nearly 

 circular, the vertical dimension slightly preponderating. The figure 

 of these surfaces is gently concave, the depression of the posterior 

 slightly exceeding that of the anterior surface. The right transverse 

 process, nearly entire, has the figure of a triangular vertical plate. 

 Its lower border is directed nearly horizontally outwards, its upper 

 border descends, its base, borne chiefly by the centrum, ascends above 

 the neuro-central suture upon the side of the arch. The free end of 

 the process, swollen and obliquely cut, exhibits appearances which 

 suggest its having borne a rib, as occurs in a few anterior caudal 

 vertebras of some existing Lizards. The depth of the transverse 

 process near its base is 14-8 centim., its length is 9*4 centim. 

 Below the transverse process the surface of the lateral aspect of the 

 centrum is depressed, being concave longitudinally and vertically. 

 Two other very imperfect vertebral centra have a slightly con- 



