LEPIDOPTERA OF NORTH AMERICA. 213 



than as calcareous divisions in the skin : but among the 

 very abundant remains of Megalonyx Cuvieri, I have never 

 found any trace of armour, with the exception of a portion 

 of an extraordinarily thick plate, whose surface presented 

 w^hat appeared ornaments in relief, so as to give it the look 

 of a fragment of some architectural decoration ; but its frac- 

 ture sufficiently proved its organic origin. 



Should this creature have really been furnished with a coat 

 of mail, it cannot be denied that this must have as much in- 

 capacitated it for climbing up trees, as all the other condi- 

 tions we have examined indisputably disqualified it for ter- 

 restrial motions. 



The family of sloths is at present confined to South Ame- 

 rica ; therefore, in the fact of their existence in the same 

 quarter during a former age of the world, we have another 

 corroboration of the result to which the history of the two 

 previous families led us, as to the correspondence of funda- 

 mental types between the extinct and existing animals in 

 that portion of the globe. In like manner, also, we find the 

 other results obtained from the same former examination re- 

 curring here, namely the much greater abundance of generic 

 and specific forms belonging to the ancient animal creation, 

 and the vastly superior size which its species attained. This 

 disproportion is even still greater if we only confine our com- 

 parison to the very district in which the fossil remains are 

 found ; for there are now none of the family I last described 

 within its limits : although I would not venture to assert, 

 that they also did not exist here previously to the disappear- 

 ance of the forests that originally clothed this country. 



(To be continued.) 



Art. II. — Remarks on the Lepidoptera of JVorfh America, with 

 occasional descriptions of Kew Species ; being the result of nine- 

 teen months travel in the United States. By Edward Double- 

 day, Esq. 



" Por aquesta razon de ti escuchado, 

 Aunque me falten otras, ser merezco, 

 Lo que puede te doy, y lo que he dado 

 Con recebillo tu, yo me enriquezco. 



Garcilasso de la Vega, Ecloga 3. 



I SHALL preface the observations I am about to make on 

 the Lepidoptera of the United States, by a few remarks on the 



