38 PROCEEDINGS OF THE NATIONAL MUSEUM vol-. 77 



EXPLANATION OF PLATES 



Plate 1 



View of the excavation where the skeleton of Palaeoscinciis rugosiden^ was 

 collected. In the middle foreground is a large plastered block containing the 

 sacrum. Photograph bj' George F. Sternberg. 



Plate 2 



Skull of Palaecoscincus rugosidens. Type. No. 11868, U.S.N.M. Superior 

 view. About one-third natural size. 



Plate 3 



Fig. 1. — Skull. Viewed from right side. 



Fig. 2. — Right ramus of Pala&oscincus rugosidens. Type. No. 11868» 

 U.S.N.M. Lateral view. About one-third natural size. 



Plate 4 



Fig. 1. — Sacrum of Palaeoscincus rugosidens. Type. No. 11868, U.S.N.M. 

 Ventral view. About one-fifth natural size. 



Fig. 2. — Tooth of Palaeoscincus asper Lambe. Type. After Lambe. 



Fig. 3. — Tooth of .Palaeoscincus costatus Leidy. Type. Inner, end, and outer 

 views. Three times natural size. After Leidy. 



Fig. 4. — Tooth of Palaeoscincus lutus Marsh. Type, a, natural size; &, 

 twice natural size. After Marsh. 



Plate 5 



Dermal bones of Palaeoscincus rugosidens. Type. No. 11868, U.S.N.M. 

 All viewed from above. 



Fig. 1. — Median pair of coossified dermal plates of the second nuchal row. 



Fig. 2. — Lateral coossified plates (left side) of the second nuchal row. 



Fig. 3. — Coossified dermal plates forming the left half of the first nuchal ring. 

 All about one-fourth natural size. 



Plate 6 



Dermal bones of Palaeoscincus rugosidens. Type. No. 11868, U.S.N.M. 



Fig. 1. — Large spine that occupies a position lateral to the third transverse 

 row of nuchal plates. Side view. 



Fig. 2. — Dermal plate from side of the animal immediately posterior to the 

 large spine shown in Figure 4. Top view. 



Fig. 3. — Spine, from the end of the second transverse row of nuchal plates. 

 Side view. 



Fig. 4. — Large double-spined plate that projected outward from the side of 

 the animal immediately above the fore leg. Lateral view. All figures about 

 one-fifth natural size. 



