Astragalus and calcaneum elongate; latter 
without trochlea ; no dermal bones ; un- 
guiculate ; teeth (sloths) ; Brady podidcz. 
Astragalus and calcaneum short, former with 
trochlea ; unguiculate ; teeth ; no dermal 
bones ; Mcgathcriidcs. 
Astragalus short, with trochlea ; on dermal 
bones ; unguiculate ; no teeth (anteaters) ; Myrniccophagidce. 
Astragalus short, with trochlea ; a carapace 
of dermal bones ; subunguiculate ; teeth 
simple (armadillos) ; DasypodidcB 
Astragalus short, with trochlea ; a carapace of 
dermal bones ; posterior feet ungulate ; 
teeth sculptured by vertical grooves ; Glyptodontidce. 
Common ancestors of the Nomarthra and Xenarthra are un- 
known. But few extinct representatives of the Nomarthra are 
known.'' A Manis has been obtained in the Sivaliks of India, 
and a genus Palaeomanis (Forsyth Major) from the Miocene beds 
of the island of Samos in the Grecian Archipelago. The P. 
gigantea is three times as large as the largest existing species. 
The same locality has yielded a species of Orycteropus. 
The existing forms of the Xenarthra appear to be widely 
separated from each other, but paleontological discovery has 
greatly narrowed the intervals between them, so that the homo- 
geneity of the order is certain. Thus the Megatheriida: are 
equally allied to the ant-eaters, the sloths, and the armadillos, 
and such genera as Nothropus and Chlamydotherium connect 
these with the Glyptodons. The carapace is rudimental in 
genera both of Glyptodontid?e and Megatheriidai. The Mega- 
theriidai also indicate a point of contact with other orders of 
V distinguished from the Perissodactyla, 
ew order, the Ancylopoda, to receive i 
88, p. 758, and Cope, 1. c. 1889. p. 153. 
