296 Bulletin American Museujn of Natural History. [Vol. XVI, 



any known fossil edentate, the resemblance being only to 

 Dasypus, and to a much less extent to Tatusia. From this it 

 seems reasonably safe to infer that it is a Mylagaulid, and that 

 this family paralleled the Armadillos in the structure of their 

 feet. 



The femur (Fig. 2, F) is nearly complete; it differs from 

 either beavers or armadillos in the position of the very large 

 and powerful third trochanter, which is placed high up on the 

 shaft, nearly opposite the second trochanter, instead of in the 

 middle of the shaft as is usually the case. The greater and 

 lesser trochanter are much as in Castor; the distal condyles 

 are wide and low, and the trochlea short, broad, and shallow. 

 Most of the tibia and fibula (Fig. 2, Fb., T.) are preserved; 

 the tibia is short and stout, beaver-like at the lower end; the 

 fibula as strong as in Castor, separate from the tibia, with a 

 vertical internal facet for the astragalus, 

 but no distal facet, and no contact with 

 the calcaneum. The astragalus (Fig. 

 2), is quite rodent-like, with moderately 

 broad trochlea defined by sharp keels, 

 internally and externally, rather small 

 neck, and broad, flattened head. Meta- 

 tarsals II to V are present, but the 

 hallux was rudimentary or absent. The 

 second metatarsal is much more slender 

 than the third and fourth, but of about 

 the same length. Mt. V is only three- 

 fifths as long as the others, but fully as 

 stout as mt. Ill and IV. The phalanges 

 of the first row are rather short, their 

 distal facets wide, not deep, moderately 

 concave from side to side. The size 

 strength of the metatarsals and proximal phalanges 

 does not appear adequate to bear the very large claw 

 (Fig. 2, A, A'^) with which they are associated, and I therefore 

 suppose that it belongs to the fore foot, where the much 

 stouter and more specialized metacarpal, such as has been de- 

 scribed as occurring with teeth of Mylagaiilus , could very ap- 



Fig. 3. Humerus of ? 

 Ceratogaulus, natural size. 

 No. 9457. Loup Fork 

 (Pawnee Creek Beds), Colo- 

 rado. 



and 



