160 Field Columbian Museum — Geology, Vol. II. 



ward at this place, but that it curved forward more after the way of birds, 

 a position compatible with the upright attitude. The whole structure 

 of the neck, the elongated vertebras, the transverse centra, and lateral 

 exapophysial articulations, the absence of transverse processes, all remind 

 one of the neck in the cryptodire testudinates, where the neck is capable 

 of much and effective antero-posterior flexion. 



The articulation of the head of the femur, with the basal plane of its 

 convexity nearly at right angles to the long axis of the bone, and the 

 posterior position of the acetabulum, carry conviction to me that the 

 femora could not have been brought parallel in the same direction with- 

 out dislocation from the sockets, whatever attitude the animal may 

 have assumed. The articulation of the distal end of the tibia further- 

 more shows that the metatarsus could not have been extended to a right 

 angle; that is, Pteranodon could not have been plantigrade. The greater 

 extension must have been between the metatarsus and phalanges; in other 

 words, the creature must have been digitigrade in ambulation. The flat- 

 tened proximal ends of the metatarsals indicate a compact and closely 

 united foot, and the bones have been so found in specimens of Pteranodon. 

 The toes in Pteranodon, and doubtless in this genus also, were practically 

 clawless, and the outer toes were much the longer. The animal was 

 incapable of seizing or holding with the feet. 



Nor could a very great flexion at the knee have been possible, as I 

 think the figures of the femur of Pteranodon ingots will indicate. If 

 the animal was quadrupedal, it must have been in a crawling attitude, 

 with both legs and arms widely extended. 



APATOMERUS MIRUS, GEN. ET. SP. NOV. 



In the University of Kansas Quarterly, vol. iii, p. 3, I described and 

 figured a remarkable bone from the Lower Cretaceous of Clark County, 

 Kansas, which I hesitatingly referred to some crocodile -like animal, 

 because I was at a total loss where else to place it, my knowledge of the 

 pterodactyl anatomy then being less than at present. The figure and 

 description are reproduced in vol. iv of the University Geological Sur- 

 vey of Kansas, p. 90, as follows: "The upper end of a femur found in 

 the same region appears to belong to the same kind of an animal, as 

 does the vertebra described above. The shape is not unlike that of a 

 human femur, with the trochanters evidently small and placed much 

 below the level of the head. The neck is stout, the head gently convex, 

 with an angular border. The shaft below the trochanters is somewhat 

 flattened from before backward, but becomes more cylindrical below. The 

 shaft is hollow, with firm walls not more than one-third of an inch in 

 thickness. The portion preserved measures 210 mm." 



