222 



BULLETIN 15 4, UNITED STATES NATIONAL MUSEUM 



fornia and is well separated, geographically, from the modern 

 tessellatus which reaches an extensive development in northern 

 Mexico, the western United States, and northern and central Lower 

 California. Structurally the two are practically identical, but 



LEGEND 



TESSELATUS 



CATALIKENSIS 

 CERALBEKSIS 



CAIJU, 



EACATDS 



rrjBIDUl 



CELERIPES 



llAXIMUS 



VAKT-fRIS 



FlGLKE 30. 



-Map showing the distuibution of tiii; foums of the tesshi.i.atls 



GROUP 



'Diaxivms is a much larger lizard and retains a more primitive 

 pattern. 



In relation to the other species of the group tessellatus seems 

 unquestionably the prototype, and furthermore, its wide distribution 

 shows it to be a progressive, plastic form. Although it is probable 

 that it rose from viaxhnus, which in turn might have risen from 



