INTRODUCTION. y 



done by Nichols. This method of representing small skulls promised more 

 accuracy than seemed to be attainable, after several trials, by hand-drawing; 

 but the figures should not be relied upon too implicitly. 



A short abstract of this paper appeared in the "Proceedings" of the 

 Philadelphia Academy for 1874. 

 I am, Sir, &c., 



ELLIOTT COUES. 

 Dr. F. V. Hayden, 



TJ. 8. Geologist, Sfc, 



Washington, D. C. 



