452 . CLASS REPTILIA. 



We shall first speak briefly concerning their organization, 

 as far as it differs from what we have already described as 

 peculiar to frogs, and generally, with respect to those points 

 in which the two genera agree, and which we have thought 

 proper to omit in our notice of rana, and reserve for the pre- 

 sent head. 



The bones of the upper region of the head in toads are, 

 for the most part, rugous at their surface. The intermaxil- 

 lary, jugal, and tympanic bones alone are beneath. The 

 bones of the lower region do not present the inequalities 

 observed in the others. 



With the exception of the symphysis of the chin, and of 

 the intermaxillaries which are free in all parts, all the bones 

 of the cranium and face are completely united by synostosis, 

 in adult individuals. The osselets of the ear are but two, 

 the malleus, and the stapes. They are very large and carti- 

 laginous. 



The toads in general are without teeth. In some species, 

 however, teeth tolerably large and curved have been ob- 

 served. The head is articulated by two condyles with the 

 atlas. 



In the toads of Europe, the vertebrae are eight in number ; 

 there are but seven in some foreign species ; their processes 

 are generally strong and pretty long ; the transverse processes 

 are broad and securiform. 



The sacrum has some transverse processes, prismatic, tri- 

 angular, and very robust ; it is long, pointed, and com- 

 pressed, without coccyx. 



The coxal lines are united in a single piece, in adults, as 

 is the case with frogs in general ; there is no appearance of 

 ribs. 



The sternum is broad, it is united in front with the furca 

 and clavicles ; it is emarginated behind and provided with 



