EDENTATA OF THE SANTA CRUZ BEDS. 



191 



First lumbar, width over transverse pro- 

 cesses 075 



First lumbar, height of neural spine . . . .036 



First lumbar, width of neural spine at 

 tip 030 



Third lumbar, length 030 



" " width of anterior face. . . .039 



Sacrum, length 7185 



Sacrum, width 01 anterior face of centrum .045 

 " " " posterior face 030 



First caudal, length of centrum 026 



" " width of anterior face 034 



First caudal, width over transverse pro- 

 cesses 115 



Second caudal, length of centrum. .... .025 



" " width of anterior face . . .032 



Second caudal, width over transverse 

 processes 084 



Third caudal, length of centrum 024 



Third caudal, width of anterior face 027 



Third caudal, width over transverse pro- 

 cesses 685 



Fourth caudal, length 025 



" " width of anterior face . . .030 



Fourth caudual, width over transverse 



processes 082 



? Seventh caudal, length 024 



" " width of anterior face . .024 



? Seventh caudal, width over transverse 



processes 062 



? Eighth caudal, length 024 



" " width of anterior face . . .020 



? Ninth caudal, length 023 



? Eleventh caudal, length 020 



" " width of anterior face .020 



? Eleventh caudal, width over transverse 



processes' 048 



? Thirteenth caudal, length 020 



Compared with those of the other species of the genus, the ribs of H. 

 longiceps are decidedly broader and heavier, though they are much more 

 slender than those of the great Pleistocene genera. The vertebral ribs are 

 long and quite strongly curved, forming a capacious thorax. The head of 

 each rib is rather broad, much depressed dorso-ventrally ; the neck is elon- 

 gate especially in the middle region of the thorax, and the tubercle is large, 

 but flat and nearly sessile. A remnant of the tubercle is present on the 

 penultimate rib, but not on the last one, which is very much shorter and 

 more slender than the former. The sternal ribs are fully ossified, but 

 their state of preservation is such that little can be determined concerning 

 their shape and number. 



Of the sternum nothing remains. 



Appendicular Skeleton. Only the distal portion of the scapula is pre- 

 served and in a much damaged condition ; apparently there were no im- 

 portant differences from that of the other species. 



The slender, elongate humerus ( Plate XXX, figs. 2, 2a ) is markedly 

 similar to that of Megalonyx and Notkrothermm. The head is small and 

 hemispherical and is set upon a rather more distinct neck than in the for- 

 mer ; the tuberosities are better developed than in either of the genera 

 named, especially the external one, which gives the bicipital groove a posi- 

 tion on the inner side of the head, instead of opposite its middle. In the 



