318 THE OSTEOLOGY OF ELOTHERITTM. 



Metatarsal III is considerably longer than the corresponding metacarpal and of a 

 different shape, being much narrower transversely and thicker in the dorso-plantar dia- 

 meter. The head is of moderate width, but the long and massive projection from the 

 plantar side gives it great thickness. On the tibial side of the head is a depression in 

 which lies the nodular mt. ii. The plantar projection bears a rounded, jdane facet on 

 each side ; that on the tibial side is for the entocuneiform, and that on the fibular side is 

 for mt. iv ; a second facet for mt. iv is formed by a shallow depression near the dorsal 

 border. The shaft of mt. iii is long, straight and slender ; it is flattened on the plantar 

 and fibular sides, rounded on the others. Toward the distal end the shaft gradually 

 expands both in width and thickness ; a very prominent and rough tubercle is developed 

 on the fibular border of the dorsal face, just above the trochlea. The latter is rather 

 low and narrow and has a prominent carina, which is confined altogether to the plantar 

 face. 



Metatarsal IV is a counterpart of mt. iii, with which it forms a symmetrical pair, 

 though the plantar projection is even larger and heavier than that of the latter and articu- 

 lates with the posterior hook of the cuboid. The connection with mt. iii is by means of 

 two facets, the dorsal one a low, rounded prominence which fits into the depression on mt. 

 iii already described, and the plantar one on the tibial side of the posterior jirojection. 

 The two metatarsals are held very firmly together, externally by the hook of the cuboid 

 am! internally by the entocuneiform. A small depression on the fibular side of the head 

 Lodges the rudimentary mt. v. The shaft and distal trochlea are like those of mt. iii. 



Metatarsal Vis even more reduced than mt. ii. It has a thickened club-shaped head, 

 which bears a facet fur the cuboid and another fur mt. iv, the two meeting at a very open 

 angle. What remains of the shaft is slender and styliform. The mode of digital 

 reduction in the pes, as in the manus, is entirely " inadaptive," the rudimentary mt. ii 

 still clinging to the mesocuneiform and preventing mt. iii from reaching that tarsal, which 

 is much diminished in size, while the ectocuneiform follows the enlargement of mt. iii. 



Kowalevsky found no metatarsals associated with E. magnum. In Anthracotherium 

 (Kowalevsky, 73, Taf. XI, Figs. A~>, 55, -">!)) the lateral metatarsals are still large, func- 

 tional and provided with phalanges; the median pair are relatively shorter and heavier 

 than those of Elotkerium, but in other respects resemble them closely. Hippopotamus 

 has very short and massive metatarsals, which do not exceed the metacarpals in length 

 and which retain the primitive mode of articulation with the tarsals. The metatarsals of 

 Sus differ from those of Elotherium in much the same way as do the metacarpals of the 

 two genera. The laterals are still functional, though much reduced, and the medians are 

 short and very heavy, with the carina? completely encircling the distal trochlea?; mt. iii 

 has acquired an articulation with the mesocuneiform, cutting off mt. ii from the ecto- 

 cuneiform. 



