G. R. Wieland — Notes on the Armored Dinosaur ia. 119 



elements is always most precarious, as we know from the fre- 

 quent dissociation of testudinate marginals. 



Dinosaur Mail from the Ceratopsia Beds. 

 Figures 4-7. 



There is strong reason to believe that owing to accidents of 

 preservation, the course of erosion from their matrix, and even 



Fig. 4. 



s ^~^ ^-*33sw- _ S' 



Figure 4. — Oblong dermal plates of Nodosaui-ida? or Ceratopsidae from 

 the Ceratops beds of Converse County, Wyoming, x A. Forms illustrat- 

 ing extreme displacement of the spinal node. In the upper figures is the 

 inner, and s the outer view of a plate, the inner left basal angle of which 

 rises as a distinct triangular spinal elevation s.s', 3 centimeters high. 

 Which is the major axis, remains uncertain. 



In the lower figures, the spinal node is at the middle of the upper edge at 

 the end of the transverse axis aa , although the trifaced feature is as distinct 

 as before. The entire form is shown by the transverse and longitudinal 

 sections aa' and bb' respectively, n being the upper inner face of the plate, 

 and its node. 



