216 THE BATH OOLITE PERIOD. CHAP. 



Stonesfield since Cuvier figured a fragment (Ossemens Fossiles, 

 Plate XXI. fig. 30) under the title of humerus ; Buckland, however, 

 having rightly named it metatarsal (Diagram LXIX). 



The specimens available for study are three, as already said, from 

 the Kimmeridge clay of Swindon ; four from Stonesfield, one of 

 them complete ; a fine distal extremity marked * Enstone/ but 

 supposed to be from Enslow Bridge. The Swindon specimens seem 

 to be a complete series of the left foot. Those of Stonesfield and En- 

 stone (or Enslow) give evidence of three toes, and they are the same as 

 the three found near Swindon. Marking them i, m, o (inner, middle, 

 outer metatarsals), we find two distal articulations of the first with 

 parts of the shanks, of the same side as the specimen from Swindon ; 

 one complete bone of the second, of the opposite side ; one distal 

 end of the third, corresponding with that just named. There is 

 also an imperfect proximal end with part of the shank. When 

 these are compared with the foot-bones of iguanodon, discovered 

 by Beckley, and described by Owen (Pal. Soc., Wealden Reptiles, 

 1856), they seem to be representatives, and especially the distal 

 articulations correspond. These foot-bones are regarded by Owen 

 as belonging to the second, third, and fourth toes, and there 

 is said to be a trace of the first attached to the second metatarsal. 

 In a very large specimen in the British Museum this trace does 

 not appear. 



These bones sometimes appear as if they had been originally 

 completely hollow, within a compact exterior substance ; but 

 even when the central parts are filled by calcareous spar, traces 

 of cellular tissue appear : in other cases nearly the whole of the 

 central parts are largely cellular. They much resemble the cor- 

 responding bones of crocodiles, and have well-defined faces of 

 articulation, which indicate free movement of the toes in a vertical 

 sense (Diagram No. LXIX.). 



A perfect specimen from Stonesfield of what appears to be the 

 second metatarsal, which agrees with the middle of the three from 

 Swindon, is measured as follows : 



inches. 



Length 13-2 



Breadth of proximal extremity . . . 2 "40 



Height of the same 4-25 



Least circumference near the distal end . . 5-80 

 Breadth of distal extremity 3-10 



