170 Bulletin American Museum of Natural History. [Vol. XII, 



position (Fig. 6). The right manus is more complete in certain 

 parts, the left manus in others. The animal is possibly a 

 Morosaurus agilis. 



The Metacarpal of the first digit is much longer and more 

 slender than in either the typical Morosaurus or Brontosaurus. 

 A single phalanx was found near it, rounding off distally and 

 quite distinct from the first phalanges of digits II, III, IV. 



The second Metacarpal is still longer and is supplied with the 

 characteristic broad phalanx i, the narrow phalanx 2, and the 

 terminal claw or phalanx 3. This digit is slightly heavier than 

 the 3d. 



The third or middle digit is the longest ; the 1st phalanx is 

 broad, the 2d and 3d are restored, the 4th is complete, and was 

 found associated in the left manus. 



The fourth digit presumably had four phalanges, but only 

 phalanx i is preserved in each case ; and it has the same broad 

 form as in D. II and III. The fifth digit is of about the same 

 length as the first, and is likewise supplied with a single phalanx 

 unformed or rounded distally, without any distinct facet for a 

 second phalanx. 



It thus appears certain that in this animal (No. 332) the middle 

 three digits were fully functional and provided with claws, while 

 the lateral digits were incomplete distally and served only to 

 support the weight of the body. 



Fore Feet of Brontosaurus. 

 Figure 7. 



The question now remains whether the fore feet of Brotitosaurus 

 were also similarly constructed upon a mesaxonic plan. 



Marsh restored {Brontosat/rus, Morosaurus) the manus like the 

 pes with a complete series of claws, the largest being on the 

 inside. 



The evidence is very positive in the two feet here mounted 

 that there ivas a deficiency of phalanges. The evidence, however^ 

 that the actual construction of the foot is as we have mounted and 

 photographed it (Fig. 7), namely, mesaxonic, is by no means posi- 

 tive. The question, in fact, cannot be definitely settled until a 

 manus is found with all the digits in position, as in the pes above 

 described. 



