526 



ZOOLOGY 



SECT. 



sternal ends, are ossified, and articulate with the sternum by means 

 of well-developed synovial articulations. In the American Ant- 

 eaters there are similar synovial joints, and the sternal ends of the 

 sternal ribs are completely bifid. In the Sloths the sternum is 

 long and narrow, and there are no synovial joints. In front the 



par 



nets 



S.OC 



FIG. 1137. Skull of Armadillo (Dasypus sexcinctus.) Letters as in Figs. 11321134. In 

 addition, peri, periotic. 



sternal ribs are ossified and completely united with the vertebral 

 ribs, but behind they are separated from the latter by intermediate 

 ribs which are less perfectly ossified. 



In the Armadillos the skull (Fig. 1137) is broad and flat, the 

 facial region triangular. The tympanic (ty.} is in some developed 

 into a bulla. The bony auditory meatus is in some cases elongated. 

 The zygoma is complete. The "pterygoids" are small, and do not 



par 



occ.cond 



FIG. 1138. Skull of Anteater (Myrmecopliaga), lateral view. aL spli. alisphenoM ; cond. condyle 

 of mandible ; cor. coronoid process of mandible ; ex. oc. exoccipital ; ext. and. external 

 auditory meatus ; fr. frontal ; ju. jugal ; Icr. lacrymal ; max. maxilla ; nas. nasal ; occ. cond. 

 occipital condyle ; pal. palatine ; par. parietal ; p. max. premaxilla ; s.oc. supraoccipital ; 

 sq. squamosal ; ty. tympanic. 



develop palatine plates. The mandible has a well-developed 

 ramus with a prominent coronoid process and a well-marked 

 angular process. 



In the American Anteaters (Figs. 1138 and 1139) the skull is 

 extremely long and narrow the facial region being drawn out into 



