298 



Annals of the Carnegie Museum. 



<mtii 



smaller development of the large * and 

 rugose tubercle which takes up a consider- 

 able portion of the tibial face of the bone in 

 the latter genus. In the recent forms, 

 especially Came/us bactrianus, the tibial 

 face of the navicular is much enlarged, 

 which is due to a still further development 

 of the large and rugose protuberance in the 

 older forms referred to above. The ecto- 

 meso-cuneiform has a rather small antero- 

 posterior (13 mm.) diameter, while the 

 transverse (10 mm.) is relatively greater 

 than in Oxydactylus and the recent camels. 

 On the fibular face the facet for the cuboid 

 takes up the anterior half of the bone and is 

 proportionally of greater size than the cor- 

 responding facet in Oxydactylus or the 

 llama. . The ecto-meso-cuneiform in Steno- 

 mylus differs from that in Camelus bactrianus 

 by the absence of the prominent tubercle 

 on the fibular side which abuts against the 

 cuboid. The ento-cuneiform is of irregular 

 triangular outline, compressed laterally, and 

 of considerable expansion antero-posteriorly, 

 especially in the distal half of the bone, 

 where a prominent tubercle is located on the 

 fibular angle, which articulates with the 

 plantar process on mt. IV in the same man- 

 ner as in Oxydactylus longipes. 



The second metatarsal is represented only 

 by a small bony nodule adhering to the 

 postero-tibial angle of mt. Ill, and has an 

 articular facet on the superior face for the 

 entocuneiform. The third and fourth meta- 



Fig. 12. Anterior and tibial views of hind foot 

 of Stenomylus gracilis. Type No. 1610. \ nat. 

 size, ec, Entocuneiform ; mt II, metatarsal II. 



* In my description of Oxydactylus longipes [Annals Car. Mus., Vol. II, No. 3, 

 p. 465, 1904, seventh line from the top) the word "small" tubercle is inserted, 

 which should read "large" tubercle. 



