558 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



of them are strikingly colored. The mongoose lemur (Lemur mon- 

 goz) is a noisy, gregarious species, noted for its agility in trees. In 

 addition to this species, the black lemur (L. macaco) is shown in the 

 monkey house. 



THE EDENTATA. 



This group of so-called "toothless'' mammals contains, in addition 

 to some peculiar Old World types of doubtful affinity, the American 

 sloths, anteaters, and armadillos. The teeth are very imperfect in 

 structure and in some forms are wholly absent. The armadillo, the 

 only edentate regularly exhibited in the zoological park, has nu- 

 merous functional teeth, but these are without a real covering of 

 enamel. Sloths and anteaters usually do not live well in captivity 

 and are shown in the collection only occasionally, as specimens can 

 be secured. 



The hairy armadillo (Euphractus vUlosus) comes from South 

 America. Numerous other species and genera are found in this 

 region and one (Dasypus novemcinctm) ranges commonly north into 

 southern Texas. The shell-like covering of the back of this form is 

 much used for making baskets for the tourist trade. Armadillos are 

 curious animals and are surprisingly quick and nimble on their feet. 

 Some species are able to roll up in a ball; the horny carapace then 

 gives them protection from their enemies. 



THE GNAWING MAMMALS. 



Among the gnawing mammals are included two very distinct 

 orders — the Eodentia and the Lagomorpha. The latter order is 

 made up of the hares, rabbits, and pikas, while all the other existing 

 rodent-like forms are members of the order Eodentia. The vast 

 majority of rodents are small creatures, like the mice, rats, and squir- 

 rels; but the order includes some very sizable living animals — the 

 porcupine, beaver, and capybara, while an extinct South American 

 member of the group was as large as a hippopotamus. The most 

 characteristic features of the Eodentia are the complete absence of 

 canine teeth and the great development of the incisors which, owing 

 to their persistant growth and the presence of hard enamel chiefly 

 on the anterior surface are worn by use to a chisel-like edge. There is 

 always a considerable space on the jaw between these cutting teeth 

 and the molariform grinders. 



Until some special means for the exhibition of living examples of 

 the smaller rodents and lagomorphs can be devised, the collection 

 must be mainly restricted to the larger forms. The common gray 

 squirrel, the red squirrel, and the cottontail rabbit roam wild within 

 the borders of the park. Among the gray squirrels will be seen nu- 



