OEDER IV. 



EDENTATA. 



Teeth simple, or none at all ; always wanting in the anterior part of the jaws. 



The Edentata of modern authors correspond to the Bruta of Linnseus, which embraced, how 

 ever, several genera to which the diagnosis, as above given, does not apply. Setting aside these, 

 (Trichechus, Elephas, and Monodon,) we have left, as constituting the Bruta of Linnseus, 

 Bradypus, Myrmecophaga, Manis, and Dasypus, to which more recent authors have added 

 Choloepus, CJdamydophorus, Orycteropus, &c., together with Echidna and Ornithorhyncus. 

 These constitute the principal living genera of Edentata, but there are several extinct ones to 

 be added to the list, as Megalonyx, Megatherium, Mylodon, &c. 



The genera of Edentata, though few in number, are yet so different from each other as to 

 admit of being arranged in three families, Bradypoda, Effodienta, and Bidaviculata. l These 

 may be briefly characterized as follows : 



I. BRADYPODA. With canine and molar teeth. Malar bone with an additional inferior process. Stomach divided. Ante 

 rior limbs very long. Mammae, pectoral. Tail very short, or wanting. Fur dry and coarse. 



Of this family, embracing the sloths proper, no representatives are found in North America. 



FAM. 2. EFFODIENTIA. Teeth uniform, or none. Malar bone simple, or wanting Muzzle elongated. Limbs short, stout ; 

 the hinder ones longest Stomach simple. 



This family, embracing the armadillos as the most prominent form, has one living repre 

 sentative in North America, Dasypus novem-cinctus, found abundantly on the lower Rio Grande of 

 Texas. 



FAM. 3. BICLAVICULATA, or MONOTREMATA. Clavicles double. Mammal papillae, wanting. Well developed marsupia 

 bones. Cloaca simple. Males provided with spurs to the eet. 



This family embraces two very extraordinary forms of animal life, the Echidna and the Orni- 

 thorhynchus, both natives of Australia. 



It is proper to state that high authority, such as that of Waterhouse and others, place the 

 Monotremata at the end of the Marsupialia. 



There is a very striking contrast between the E/odientia, as characterized above, and the 

 Bradypoda. 



In the latter, the structure of the animal is adapted to a residence upon trees, and it is 

 only exceptionally that the sloths are found on the ground. In the armadillos, on the other 

 hand, the solid covering, and the long fossorial claws, indicate a terrestrial habitat, and that 

 rather beneath than above the surface. The food of the two groups is equally diverse ; that of 

 the sloths consisting of the leaves and twigs of trees, while the armadillos seem created espe 

 cially to keep in check the myriad insects of tropical regions, and especially the ants, the most 

 abundant of all. 



'Wagner, Suppl. Schreber, IV, 130. 



