276 FIELD CoLuMBIAN MustumM—GEo tocy, Vou. I. 
coraco-scapule, an incomplete fore foot, a disarticulated sacrum, an 
ilium, a tibia and various dorsal and caudal vertebrae, together with a 
‘fine series of cervical and dorsal vertebre not yet removed from the 
matrix. 
An almost complete fore leg (Plate XL), collected by the Museum 
expedition of rg900 near Fruita, Colorado, shows some interest- 
ing characteristics not hitherto pointed out. The specimen was 
found in the uppermost stratum of the green shale which represents 
the lower Como Beds in this locality.* Its dimensions are a little 
greater than those of WZ. grandis, Marsh, but the proportions are so 
nearly the same that it seems desirable to refer it to that species. 
The entire specimen save the foot bones had been weathered out of 
the matrix and certain parts lost entirely, but its chalcedony filling had 
preserved the fragments so well that the whole has been restored with 
approximate accuracy. 
The chief point of interest is in the foot-structure which does not 
agree with the mesaxonic theory of the structure of the front foot in 
Sauropoda as advanced by Osborn.* On the contrary the first digit 
in this specimen bears a stout claw which is directed inward and 
shows evidence of having been semi-opposable. A second specimen 
belonging to a smaller species has a similar structure. 
Of the carpal bones only the radiale is preserved in this speci- 
men (Pl. XLI, Fig. 1). Metacarpal I is not so stout in proportion as 
that of Brontosaurus, but 1s stronger and noticeably shorter than the 
succeeding members of the series. Its proximal end presents to the 
radiale a broad ovoid surface with the long diameter directed meso- 
anteriorly. The shaft is twisted so that the axis of the distal end is 
rotated inward. Its articular surface for the first phalanx slopes up- 
ward and backward from the anterior to the postero-internal border. 
Phalanx 1 of this digit 1s short and prismatic, articulating closely with 
the carpal as well as with the stout ungual which it bears. The digit 
as a whole is thus directed mesially with the ungual inclined back- 
ward, and as before stated was probably semi-opposable. 
Metacarpal II is longer but almost as stout as the first. Its 
proximal end is broadest meso-laterally while the axis of the distal 
end is rotated slightly toward the mesial side. Phalanx 1 is very 
unlike its homologue of the first digit. It is flattened vertically and 
articulates with the metacarpal by an almost plane surface, while the 
distal facet is convex and flanked on either side by rugosities for liga- 




*Riggs, Dinosaur Beds of the Grand River Valley of Colorado, Pubs. Field Columbian 
Museum, Geological series, Vol. I, No. 9. 
{Bulletin of the American Museum, Vol. XII, p. 168. 
