MOODIE: ARMORED CRETACEOUS DINOSAUR. 269 



spine measures 80 mm. from the point of its inception to the 

 tip, and the main spine measures 16 inches from tip to tip. 

 At its widest part it is 100 mm. in breadth. The surface of the 

 bone is pitted with irregularly placed cavities as though it were 

 encased with horny substance. 



The exact position of this large spine on the body of the 

 animal is, of course, largely a matter of conjecture, since it was 

 found broken and disassociated and mingled with various 

 other parts of the skeleton, but it seems best to locate it back 

 of the pelvic shield, since the caudal vertebrae are much stouter 

 than the dorsal ones and since there is no evidence of any armor 

 excepting the small bony scutes anterior to the pelvis. The 

 spine is totally unlike anything described for any other stego- 

 saurian dinosaur. 



The dermal plates, represented in plate LVI, figs. 2 and 9, 

 are massive and of a compact texture. Their position on the 

 skeleton is a puzzle. The plate represented in plate LVI, fig. 

 9, is not entire. It is asymmetrical, one side being crossed by a 

 rather high ridge. Its upper surface has pittings and grooves. 

 The under surface is smooth and rounded. It is possible that 

 this is a portion of another girdle similar to the one described 

 below. That it is not a part of that girdle is evident from its 

 proportions. The plate measures 105 mm. in diameter. The 

 other dermal plate (plate LVI, fig. 2) is apparently complete, 

 with a broad surface for articulation with some element which 

 is now lost. This plate is concavo-convex. It measures 

 140 mm. across in the longest diameter. It is without vascular 

 markings of any kind, but is smooth as though it were entirely 

 embedded in the flesh of the animal. 



The part of the girdle represented in plate LVI, figs. 6 and 7, 

 is like the last described plate in that it is of a compact texture. 

 In the girdle the upper surface is pitted, and crossed at regular 

 intervals by rather high ridges the sides of which are slightly 

 concave. This bone at once reminds one of the similar ele- 

 ment figured and described by Lambe (29) as occurring in 

 the Stereocephalus form. Lambe (29) however, located the 

 girdle back of the head, and if his interpretation of the large 

 fragment which he calls the skull is correct such a location 

 would be quite plausible. The present girdle differs in a great 

 degree from that described by Lambe, since it is asymmetrical 

 and had a mate on the opposite side, of which there are frag- 

 ments in the collection. It differs further in being a solid mass 



