APPENDIX. 417 



but it is supposed to be opthiosaureus of Dandrige, corresponding 

 to the anguis ventralis of Linnceus, figured by Catesby. 



The shells afford a rich amount of an undescribed species. The 

 whole of the univalves and bivalves received from Messrs. School- 

 craft and Douglass have been assembled and examined, with all 

 I possessed before, and with Mr. Stacy Collins's molluscas brought 

 from the Ohio. Mr. Barnes is charged with describing and de- 

 lineating all the species not contained in Mr. Say's Memoir of the 

 Productions of the Land and Fresh Waters of North America. The 

 finished work will be laid before the Lyceum, and finally be 

 printed in Mr. Silliman's Neio Haven Journal. The species by 

 which geology will be enriched will amount, probably, to nine or 

 ten. (C.) We shall endeavor to be just to our friends and bene- 

 factors. S. L. MITCHELL. 



For Gov. Cass. 



Notes. 



(A.) 



An animal similar, in some respects, has been subsequently 

 found on the Straits of St. Mary's, Michigan, a specimen of the 

 dried skin of which I presented to the National Institute at 

 Washington ; but, from the absence of the head bones and teeth, 

 it is not easy to determine whether it is a sciurus, or arctomys. 



(B.) 



The duplicature of the cheeks of this animal having been ex- 

 tended outivardhj in drying the skin, was left in its rigid state, 

 giving it an unnatural appearance, which doubtless led to the in- 

 credulity of Cuvier when he saw the figure and description of Dr. 

 Shaw. Dr. Mitchell was led to a similar error of opinion, at first, 

 as to the natural position of these bags ; but afterwards, when the 

 matter was explained to him, corrected this mistaken notion. 



(C.) 



By reference to the descriptions of Mr. Barnes and Mr. Lea, 

 recited above, the number will be seen to have exceeded this 

 estimate. 



XVI. 



Mas Busarius. Vide Medical Repositor]]^ vol. xxi. p. 248. 

 27 



