98 PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 



The navicular is of the usual armadillo type, from which it departs less 

 than does that of Stegotherinm. 



The entocuneiform is like that of Proeutatus, except for its greater 

 length. The mesocuneiform is, as usual, extremely small, and the ecto- 

 cuneiform very large. The cuboid differs in several respects from that of 

 the other genera ; it is larger, has a more massive and prominent plantar 

 hook and a much less oblique calcaneal facet; the distal end is covered 

 by the large facet for metatarsal IV, that for metatarsal V is extremely 

 small and confined to a projection from the antero-external angle. 



Metatarsal I is a little longer and stouter than metacarpal I, but the 

 hallux is greatly reduced and hardly so long as metatarsal II. 



Metatarsals II, III and IV are of nearly equal length, but, owing to 

 the arrangement of the tarsals, metatarsal III extends farthest distally, 

 while metatarsals II and IV make a nearly symmetrical pair; these bones 

 are all slender and elongate, much exceeding the corresponding meta- 

 carpals in length and in striking contrast to the short, heavy metatarsals 

 of Proeutatus and Stegotheriiim. A very characteristic peculiarity of the 

 metatarsals of Peltepliilus is the high, pulley-like, deeply grooved distal 

 trochlea, which is so exceedingly different from that seen in other arma- 

 dillos ; the fossa on the dorsal side of the shaft, just above the trochlea, is 

 also, especially that of metatarsal III, much deeper and more conspicuous 

 than in any of the other genera. Metatarsal II has a curved shaft, of 

 roughly trihedral section, and that of metatarsal IV is its counterpart, 

 while the shaft of metatarsal III is straight and of subcircular section. 



Metatarsal V is very much reduced and shorter than metatarsal I, though 

 somewhat heavier ; its trochlea is almost plane and quite concealed by the 

 first phalanx. 



The phalanges are in remarkable contrast to those of the manus, being 

 so much smaller that it seems difficult to believe that they belonged to the 

 same animal. In digit I the proximal phalanx is short, slender and 

 slightly contracted in the middle; in digits II, III and IV this phalanx 

 becomes successively shorter and broader, while in V it is very much 

 shortened, almost cubical and with nearly plane articular faces. 



The second phalanx is longest in digit II, somewhat shorter and much 

 stouter in II, still shorter in IV and shortest of all in V. 



The unguals are altogether different from those of the manus, being 

 short, broad, depressed, very blunt and hoof-like rather than claw-like. No 



