"76 Absence of Deserts in the United States. 



cupied by the alveolar sockets, five inches and eight-tenths. The 

 crown of the tooth presents no protuberances, but resembles that 

 of the sloth ; the roots are hollow^. 



"There is also in Mr. Graves' collection, a tibia, nearly perfect, 

 from the right leg : the segment of a flattened sphere, on w^hich 

 the . external condyle of the femur moves, is rather more de- 

 pressed, than in the specimen from White Cave. Other marks 

 and peculiarities are observable on this bone, not found on that 

 of the Megalonyx of White Cave, but they are probably due to 

 a difference in the age of the individuals.* 



" Of the remains of Mastodons in this collection, I shall only 

 notice the recomposed cranium of an animal, not yet adult, but 

 which appears nearly perfect. The tusks are of an enormous size, 

 and there exists a very deep cavity immediately anterior and below 

 the aperture for the anterior nares, for the lodgment or origin of 

 the large muscles which moved the trunk. This cranium does not 

 appear to differ specifically from that of a specimen in Peale's 

 museum. New York, and which gave occasion to the too hasty 

 proposal of a new genus, under the designation ' Tetracaulodon,' 

 or * four tusked ;' a name which would be more appropriately 

 applied to the wild boar, the Hippopotamus, and many other 

 quadrupeds which are furnished with four tusks. 



R. HARLAN." 



THE UNITED STATES ARE EXEMPT FROM DESERTS, AND 

 ALL THE EVILS CONSEQUENT THEREON. 



The physical conformation of North America, precludes all 

 possibility of deserts, or extended wastes. Those arid regions re- 

 sult from a want of moisture, and attach to those extended 

 plains in the neighbourhood of the tropics, too vast and dispro- 

 portioned for the quantity of rain that nature has assigned to 

 them. They drink, and are still dry. The clouds of heaven 

 float over them in vain. Like Pharaoh's kine, they devour all, 

 but change not their miserable condition. 



*From these very lucid details, it is evident that if persons in possession of iso- 

 lated osteological remains of this character, would submit them to the inspection 

 of an experienced comparative anatomist, we should soon be in a situation to re- 

 construct this, and many other extinct animals of this continent. We invite gen- 

 tlemen to correspond with us on this interesting subject ; a rude drawing will be 

 sufficient to enable us, if required, to apprise them of the intrinsic value of the 

 objects represented. — [Editor.] 



