EDENTATA OF THE SANTA CRUZ BEDS. 63 



widest part of the bone and bears an oblique, saddle-shaped facet for the 

 entocuneiform ; the shaft is short and wide, contracting distally and the 

 distal trochlea is narrow, concave and without a carina. 



Metatarsal II is much longer than metatarsal I and slightly exceeds 

 metacarpal II in length ; the proximal end is broad and extends over the 

 head of metatarsal III. Owing to the small size of the mesocuneiform, 

 the head of metatarsal II is wedged in between the ento- and ectocunei- 

 forms, with both of which it articulates. The shaft has an oblique 

 appearance, on account of the deep pit on the fibular side for the head of 

 metatarsal III, but widens much distally ; the trochlea is low and broad, 

 saddle-shaped, and with faintly marked carina. 



Metatarsal III is much the longest of the series and somewhat longer 

 than metacarpal III ; the proximal end is broad and has a plane, obliquely 

 placed facet for the ectocuneiform, while the depressed shaft narrows dis- 

 tally, but expands quite suddenly to form the broad, semicylindrical 

 trochlea, which has a very low keel. 



Metatarsal IV is a little shorter than metatarsal II, with which it forms 

 a nearly symmetrical pair; it is therefore both actually and relatively 

 much longer than metacarpal IV; the proximal end is widened by an 

 extension to receive the head of metatarsal V, and the cuboid facet is 

 plane and oblique ; the shaft is depressed and contracts towards the 

 middle, expanding again distally ; the semicylindrical trochlea has the 

 most prominent keel of the series. 



Metatarsal V is but little shorter than metatarsal I and much longer 

 than metacarpal I ; it is broad and thick, with very low, saddle-shaped 

 trochlea, and the keel is a mere tubercle. 



The phalanges are less individualized than those of the manus, though 

 they differ somewhat in the various digits. The proximal phalanx of the 

 hallux, though slender and elongate, is less so than that of the pollex. 

 In digit II this phalanx is somewhat shorter and much heavier, while in 

 the other digits it is very short, broad and depressed and successively 

 more so from the third to the fifth. The second phalanx is most elon- 

 gate and slender in digit II, while in III, IV and V it is much shorter 

 and wider; in these three digits it is of nearly the same length as the 

 proximal and of similar depressed shape, but rather more slender. 



The ungual phalanges are extremely characteristic and differ widely 

 from those of the manus, being much shorter, wider, more depressed and 



