EDENTATA OF THE SANTA CRUZ BEDS. 85 



between the unguals of digits III and IV is much greater than in Pro- 

 zaedius. Digit V has still shorter phalanges of similar shape. 



The comparative length of the digits is in the following order : II, III, 

 IV, ?I, V; the greater length of II is entirely owing to the elongation of 

 the first and second phalanges, while in III it is due to the metacarpal and 

 the great size of the ungual. In digit IV the reduction of the metacarpal 

 shortens the whole digit, while in V all the elements, except the claw, are 

 much shortened. 



As a whole, the proportions of this manus distinctly resemble those of 

 Cabassous (Xenurus) ; it is of a decidedly more advanced and specialized 

 type than the manus of Dasypus. 



Though of the same general plan, the pelvis (Plate VI, fig. 26) differs 

 considerably from that of Prozaedius ; the ilia do not diverge posteriorly, 

 but pursue a nearly parallel course ; they are narrow, trihedral and only 

 moderately thickened and everted at the anterior end, where they extend 

 beyond the sacrum ; the peduncle is short, broad and depressed, with 

 prominent borders and nearly flat iliac surface. A great difference from 

 the preceding genus is the formation of a pubic symphysis, sufficient of 

 the broad, stout pubes remaining to demonstrate this. The ischia are 

 unknown. 



The femur (Plate VI, fig. 26), of which only the proximal half is known, 

 is quite unlike that of Prozaedius and resembles more the peculiar femur 

 of Proeutatus ; the head is quite small and almost sessile and has a very 

 large fossa for the round ligament; the great trochanter is relatively 

 enormous, far larger than in the preceding genus, rising far above the 

 head, and, though laterally compressed and only moderately expanded at 

 the free end, has yet a large antero-posterior extension, which increases 

 proximally; the anterior border is extended well down the shaft as a 

 prominent ridge, while the posterior border continues to the second tro- 

 chanter as an intertrochanteric line ; there is no distinct digital fossa, but a 

 depression behind and below the head ; the second trochanter is also 

 very large, arising immediately below the head, and of the usual form ; 

 the third trochanter is a very narrow, but very prominent antroverted 

 hook. 



So much of the shaft as is preserved differs markedly from that of Pro- 

 eutatus, not being antero-posteriorly compressed and flattened, but slender 

 and trihedral, with large, thin-walled medullary cavity. 



