ART. 16 



FOSSIL KEPTILES FROM MONTANA GILMOEE 



9 



forms to the curved maxillary row (fig. 3B). Posterior to the last 

 alveolus the superior border curves gently upward as a pointed 

 process that is enveloped by the coronoid which appears to be 

 astride it. On the internal side the splenial completely covers 

 Meckel's groove. On this side a horizontal ridge is developed 

 which becomes more prominent anteriorly where it finally forms the 

 posterior boundary of the symphysial part of the dentary. Here 

 the main body of the bone changes from a vertical to a horizontal 

 position. The union of the dentary with the posterior elements 

 can not be determined. 



FiGUEB 3. — Right ramus of Palboscincus edgosidens. Type. No. 11868, 

 U.S.N.M. A, Inner view ; B, Supeeior view. Both one-third natural 

 SIZE. Art., Articular ; C, Coronoid ; 8., Symphtsical border 



The coronoid sends forward an anterior portion that laps along 

 the supero-posterior portion of the dentary as shown in Figure 3. 

 It forms much of the anterior border of the mandibular fossa, which 

 is extensive, A second process is sent forward on the outside of the 

 dentary but its full extent can not be determined. Posteriorly, how- 

 ever, it is so fully fused that its limits can not be recognized. 



The articular is prominently developed extending inward as a 

 shelf-like platform that, viewed from above, is subtriangular in 

 shape. The cotylus is shallowly concave antero-posteriorly, being 

 divided into two parts by a low, rounded, longtiudinal ridge. The 

 prearticular is probably present but is thoroughly coossified. 



