444 H. G0VIER SEELEY ON" iVIACRTJROSATIRTTS SEMNTTS. 



irregular ; the posterior is subconvex, with a transverse impressed 

 groove (fig. 1). The articular margin is somewhat worn ; but on the 

 base the centrum is somewhat flattened, and on one side posteriorly 

 there is a faint slight ridge such as might indicate a chevron bone, 

 had there been any other reason for suspecting such a structure. The 

 neural arch seen from above (where it is worn) is wedge-shaped, 1 

 inch wide in front, with the straight sides converging posteriorly 

 in a distance of 1J inch to J an inch. The superior surface of the 

 arch is flattened, and rounds into the sides; it is straight and in- 

 clined forward ; but the extremities of the processes are broken both 

 before and behind. In front the height from the base of the cen- 

 trum is 1-J-inch; 1J inch further back the height is 2 J inches. 

 The antero-posterior extent of the pedicles of the neural arch be- 

 tween the concave notches in front and behind it is 1 inch. The 

 centrum is 1J inch deep at the posterior articulation, while in the 

 middle of the neuro-central suture it is 1 inch deep. 



In the 'Annals of Natural History ' for November 1871, I de- 

 scribed and figured under the name of Acanthopholis platypus the 

 metapodium of a large animal. As the middle bone is 6 inches 

 long, and the bones measure 9 inches over their proximal ends 

 from side to side, and there is no other evidence of bones of Acan- 

 thopholis reaching a corresponding size, I am inclined to speculate 

 on the probability of those bones being a part of the foot of 

 Macrurosaurus, probably the metacarpal bones. If the remains 

 both belong to the same genus, then Macrurosaurus would probably 

 indicate a gigantic modification of the Crocodilian type of Dinosaurs. 



