30 OSTEOLOGY OF PTERANODON. 



carpal, when in the supposed natural position. The lateral carpal of this example has 

 two foramina on opposite sides of the bone. 



In another example of Pteranodon sp.. No. 2683, the two larger carpals of the right 

 wing are preserved with but little distortion, and the lateral carpal, although found in 

 two separated fragments, has been restored well enough to be photographed in its 

 supposed natural position relative to the main body of the carpus. The writer is not 

 aware that the three carpals have yet been found in true contact in any example of the 

 genus, and until either this is done or the lateral carpal is found in contact with the 

 pteroid bone, it will remain an open question which end of the lateral carpal is rightly 

 supported by the process arising from the radio-palmar angle of the distal carpal. Com- 

 parison with the European pterodactyls offers little aid toward the solution of this prob- 

 lem. In support of the position of the lateral carpal in the accompanying figures, it 

 may be said that the articular sockets characterizing the ends of the bone are of une- 

 qual size, and the end of the bone bearing the larger socket may be reasonably sup- 

 posed to be turned toward the distal carpal, inasmuch as the articular process of the 

 distal carpal is considerably larger than the proximal head of the pteroid. In Plate XXII, 

 figure 4, the main body of the carpus of No. 2683 is seen from the palmar side, as 

 found in contact with the proximal end of the large fifth metacarpal. In figure 5, the 

 carpus has been removed from the matrix so as to exhibit the dorsal side. 



The form of the great metacarpal, recognized by most paleontologists as the fifth, is 

 shown in Plate XXI, taken from the wing bones of Pteranodon sp., No. 2425. The 

 dorso-radial surface of the bone is here presented to view. It will appear at a glance 

 that all the sections of this wing are more or less dislocated. The characteristic forms 

 of metacarpals II, III, and IV may be learned from such parts of these bones as are 

 preserved, all three appearing to consist of extremely slender rods of bone closely 

 pressed to the great metacarpal and expanding distally into rounded condyles for the 

 articulation of the phalanges of the short clawed fingers. The greater part of the 

 pteroid bone remains with its proximal head almost in contact with the carpus. Its 

 shaft, however, has been turned from its normal position. In most specimens, the pteroid 

 is directed nearly toward the head of the humerus. A complete pteroid may be seen 

 in Plate XXIII, figures 1 and 2, showing the wing bones of Pteranodon sp., No. 1181. 

 The bone bears a slight resemblance to the distal parts of the lateral metacarpals, next 

 to which it lies in the matrix. It is, however, easily distinguished by its greater cur- 

 vature at the articular end and by its stouter shaft. The question whether or not the 

 so-called pteroid should be properly identified as the metacarpal of the first digit of 

 the manus need not be entered into here, as there is no new evidence to be offered in 

 support of either view. 



Previous attempts to assemble the phalanges of the three clawed fingers of the hand, 

 viz., digits II, III, and IV, have not been entirely successful. The best diagrammatic 

 reconstruction of these parts was given by Professor Williston in his paper : " On the 

 Osteology of Nyctosaurus," p. 145. In explanation of the figure, he states : " I give 

 herewith a diagrammatic figure of these parts in Pteranodon, based on a specimen in 

 which nearly all the bones were present and in position, some of the terminal phalanges 

 only being misplaced, and one or two of the fourth finger missing. In a former paper 

 I stated that the phalanges of the hand were of two kinds, long and short. Possibly 

 this is the case in some of the smaller species, but I think not. I doubt not that the 

 small phalanges there described were from the foot, and had become misplaced and 



