158 MEMOIRS OF THE CARNEGIE MUSEUM 
the fossil the sigmoid notch is wide internally, with a strong supporting rib-like 
brace, which unites with the shaft below, and is relatively heavier than that seen 
in Aplodontia. The olecranon process is more produced upward, and hasa stronger 
muscular attachment in S. fossor than in either Cyncmys or Aplodontia. Tn the type 
the shaft of the ulna is much less curved than that of the radius, and terminates in 
a round knob, which articulates with the carpals. 
Fic. 3. Fore-limb of Steneofiber fossor in position ; somewhat larger than natural size. 
The accompanying figure (Fig. 3) represents the fore-limb and foot of S. fossor in 
position. The limb presents a striking similarity to that of other fossorial rodents, 
and approaches that of the mole in its position. The elongated and narrow scapula 
of the mole, the heavy clavicle, the strongly built humerus, and the broad foot with 
the long and powerful unguals, is rather suggestive of the habits of this animal, 
which was probably fossorial to a considerable degree. 
The Fore-foot. — Of the carpals there are, unfortunately, only the cuneiform, unci- 
form, and trapezoid, the first and second metacarpals, and the first phalanx of the 
