47 



cioiis observations. We hope he may be 

 induced to resume his labors. 



The essays of Messrs. Lesueur and Say 

 have illustrated, in an eminent degree, the 

 history of the genus Testudo, which now in- 

 cludes fifteen North American species. The 

 Saurian division of reptiles, comparatively 

 few^ of which are found in this country, has 

 been much enlarged by the addition of se- 

 veral species, of the genera Agama, Lacerta, 

 Scincus, and Ameiva. Among the Ophidia 

 our researches have been extremely limited. 

 The expedition before alluded to has furnish- 

 ed us with excellent descriptions of seven, 

 and the Journal of the Academy with three 

 additional new species. The Batrachia have 

 only very recently been investigated, and 

 although their study is attended with pecu- 

 liar difficulties, as they frequently change 

 their color and markings when alive, and 

 still more after death ; yet our naturalists 

 have not been discouraged by these unpro- 

 pitious circumstances. We are chiefly in- 

 debted to our associate. Captain Le Conte, 

 for the additions made to this department. 

 His long and familiar acquaintance with 

 species, has given additional interest and 



