438 THIRD REPORT — 1838. 



Hkad Coronal breadth of cranium 10 



Mesial thickness of the bony plate form- 

 ing the palate and the basilar surface of 



the nasal passage 2 



Mesial height from the surface of the palate 

 to the concavity of the coronal surface, 

 about the rostral margin of the rostral 



molar 8 



Greatest height of the fragment of the 

 head from the palatal surface in the di- 

 rection of the socket of the third molar 12 

 Vertebra. . . Breadth of the transverse process of the atlas 14 



of the fifth cer\'icEd 9 



of one of the largest dorsal .... 12 

 of a caudal vertebra, supposed to 



be that next the sacrum 25 



of the seventh of the 12 caudal 



which remain 10 



of the smallest caudal 4 



Length of the body of the atlas 3 — 



of the fifth cervical 3 — 



of one of the largest of the dorsal . 4 -f- 



of one of the lumbar 5 



of six caudal 4+ 



of the smallest caudal 3 



In the first three vertebrae of the tail in which the length is 

 diminished, that dimension is gi*eatest on the upper or dorsal 

 aspect, indicating that about the middle the tail had a ten- 

 dency to curvature downwards and forwards. 



Longest spinal process of a dorsal vertebra 16 



Spinal Canal. . Width in atlas 3 



in fifth cervical 3 + 



at the pelvis 4 



The ribs of the megatherium were connected to the sternum 

 by osseous attachments. 



Length of the longest rib which has been found (without 



its sternal attachment) 36 



of the shortest rib found (probably the first). ... 15 + 



Greatest breadth of the shortest rib 5 



of the longer ribs 3"5 



Thickness of the longer ribs 1 "8 



Sternum .... Breadth of the rostral portion 8 



Mesial length of the same 10 



1 



