322 ARMADILLOS. 



seven molars on each side the upper jaw, and a tail as long as 

 the body ; it inhabits Cayenne and the northern parts of Brazil. 

 The Das. septem-ciwctus. L,, (D. hybridus, Desm.)(l) has hkewise 

 seven molars on each side of the upper jaw, and a tail much shorter 

 than the body. 



The Armadillos of the subgenus Euphractus, Wagler, to which 

 the term Dasypus is restricted by F. Cuvier, are distinguished by 

 having the anterior tooth, which is shaped like the succeeding 

 molar, implanted in the maxillary bone. The species of which the 

 dentition is figured by M. F. Cuvier (2), is the Dasypus sex-cinctus of 

 Linnaeus, the Weasel-headed Armadillo of Grew. It has ^^ = 38 

 teeth. Those of the upper jaw gradually increase in size to the 

 sixth, and diminish from the seventh to the ninth : they present 

 an elliptical, transverse section, w^hich is narrowest in the small 

 anterior teeth. The two anterior teeth of the lower jaw being in 

 advance of the intermaxillary tooth, are, with it, arbitrarily held 

 to be incisors : they are compressed, but are terminated by obtuse 

 crowns : the rest of the series, from which the incisors are not 

 separated by any remarkable interval, gradually increase in size 

 to the penultimate molar : they have the same alternate position 

 and obliquely worn grinding surfaces as in the Tatusiae. 



Among the extinct species, that forming the type of the genus 

 called by M. Lund Euryodon is distinguished from all existing Arma- 

 dillos by having the teeth compressed from before backwards, in- 

 stead of laterally ; but the grinding surface consists, as usual, of 

 two facets, which meet at a more or less acute angle in a transverse 

 ridge (3). 



In a second extinct genus, Heterodon, Lund, the teeth exhibit 

 much less conformity in shape and size than in the existing Arma- 

 dillos. Both the anterior and posterior molars are small and 

 conical ; while the penultimate and ante-penultimate are much 

 larger, the former being oval, the latter heart-shaped in transverse 

 section. 



(1) This species occurs only in the extra-tropical part of S. America. 



(2) Log. cit. PI. hxix. 



(31 Blik paa Brasiliens Dyreverden For Sidste Jordomv^ltning, af Dr. Lund, Kjobenhavn, 

 ']to. p. 7. 



