444 Mr. Clift on the Megatherium. 



altogether deficient, merit more particular attention here. Of these, twelve 

 remain; but they are, without doubt, not the entire number; some inter- 

 mediate, and the extreme ones are evidently wanting. The twelve which are 

 preserved become regularly smaller towards the last. The first eleven are 

 ])erforated for a continuation of the spinal nerves, and have spinous and arti- 

 cular processes, in addition to the transverse, which the twelfth also possesses. 



They have the inferior spines (i. e. the chevron or V-shaped bones), mani- 

 festing- in this their relation to other Edentata, as the Myrmecophaga and 

 Dasypodae*. 



Their admeasurements, as they at present follow in gradation, are : 



1st and 2nd, very imperfect, and their dimensions uncertain. 



.3rd of the caudal vertebrae present. Ft. 



From the end of one transverse process to the other 1 



Transverse diameter of anterior articulating surface 



Antero-posterior diameter of ditto 



4th of the series. From the end of one transverse process to the other 



5th ■ From ditto to ditto 



6th From ditto to ditto 



7th From ditto to ditto 



,Sth From ditto to ditto 



9th From ditto to ditto 



1 Oth From ditto to ditto 



1 ith From ditto to ditto 



1 2th From ditto to ditto 



Of the ten chevron or V-shaped bones, or inferior spinous processes 



Ft. In. Lines. 



The 1st.— Length 



Breadth at the base 



Length of its cavity 



Breadth of ditto 



2nd. — Length 



3rd. — Ditto 



4th. — Ditto 



5th. — Ditto 



6th. — Ditto 



7th. — Ditto 



8th. — Ditto 



9th. — Ditto 



10th. — Ditto 



* Though there arc only twelve caudal vertebra, and ten chevron bones extant, the number 

 of vertebra; composing the tail was probably not fewer than eighteen. The extremity of the tail is 

 incomplete by, perhaps, two vertebrae, and the smallest chevron bone belongs to the fourth or fifth 

 from the tip. Some, also, of the larger chevron bones have not their corresponding vertebrae. 



In. 



Lines 



3 







5 



6 



5 







11 







10 



6 



9 



6 



8 



6 



7 



7 



6 



6 



6 







5 







3 



3 











5 







2 



2 



2 



3 



9 







8 







7 







6 







5 







4 







3 



2 





9 



2 



6 



