Peterson : Description of Stenomylus. 299 



tarsals are more completely fused than the metacarpals. They are 

 also somewhat longer and slenderer. Metatarsal III is slightly heavier 

 than mt. IV, although the shaft of the latter has a greater antero- 

 posterior diameter in the middle region, causing an asymmetrical 

 appearance of the posterior face of the canon -bone. The head of 

 mt. Ill rises slightly above that of mt. IV and has a larger facet for 

 the tarsals than the latter. The plantar processes are as prominent 

 as in Oxydactyhis and carry the articulations for the entocuneiform 

 and the cuboid in a similar manner. The minute trace of an articular 

 surface on the postero-fibular angle of the cuboid and a correspond- 

 ingly small facet on the postero-fibular face of mt. IV would seem 

 to indicate that there might have been present a rudiment of a fifth 

 metatarsal in the type specimen. 5 As in the metacarpals the dis- 

 tal end of the canon-bone is not much expanded, and the trochleae 

 of the individual bones are very little wider than the shafts. The 

 carina is confined to the plantar face and is somewhat narrower, though 

 of about the same relative development as in Lama huanaco. The 

 proximal row of the phalanges are present in the type. They are 

 long and slender, though proportionally shorter than in Lama huanaco, 

 and in this respect more nearly like those in Oxydaclylus. As in the 

 latter genus the proximal articulations are more widely separated by 

 the deeper grooves for the metapodial keels than is seen in the recent 

 genera, and the shafts are more nearly cylindrical. The greater por- 

 tion of the distal articulation for the second row of phalanges is on 

 the plantar face of the bone ; a distinctively Tylopodan character. 



Measurements. 



mm. 



Length of femur from head to distal end 205 



Transverse diameter of head of femur 19 



Anteroposterior diameter of head of femur 19 



Transverse diameter of distal end of femur 34 



Greatest length of tibia 248 



Greatest antero-posterior diameter of head of tibia 53 



Greatest transverse diameter of head of tibia 38 



Greatest transverse diameter of distal end of tibia, fibula not included... 30 



Greatest antero-posterior diameter of distal end of tibia 20 



Height of tarsus from top of external condyle of astragalus to distal 



articular face of cuboid 45 



5 In another specimen (No. 1340, Car. Mus. Cat. Vert. Foss. ), referred to the 

 same species, the second and fifth metatarsals are present and the two are of about 

 the same size. 



