108 PROCEEDINQS OF THE NATIONAL MUSEUM. vol. 51. 



The specimen presents considerable parts of the skull, most of 

 the anterior half of the vertebral column, six caudal vertebrae, con- 

 siderable parts of the limbs, a fragment of the scapula, a few frag- 

 ments of the pelvis, and a considerable number of the osseous plates 

 which made up the carapace and sheath of the tail. Undoubtedly 

 much more of the skeleton was present and might have been saved 

 had it been exhumed by a practiced hand. 



Professor Cope based the species Glyptodon petaliferus'^ on one- 

 half of a single dermal plate which had been found in Nueces 

 County, Texas. This fragment was figured in 1889,^ showing the 

 object two-thirds the natural size. The diameter was given by Cope 

 in his original description as 45 mm. ; that of the central area as 

 17 mm., the thickness as 15 mm. Where the type is now is not known. 



Of the carapace and tail sheath of the Wolfe City specimen there 

 are present about 80 plates. Although these constitute but a small 

 part of the whole, there are enough to show the various forms which 

 these plates assumed. In diameter they vary from 35 mm. to 50 mm. 

 There were some, no doubt, which were smaller and others larger 

 than those which are preserved. In Cope's specimen the central area 

 had a diameter equal to three-eighths of that of the plate. In the 

 animal here described the diameter of the central areas of the plates 

 varies from the relative length given by Cope up to seven-tenths 

 or more of the diameter of the plate. In some cases the central area 

 occupies practicall}^ the whole area of the plate. In thickness they 

 vary from 14 mm. or less up to 42 mm. As to the external sculpture, 

 there appears to be nothing shown in Cope's description and figure 

 that can not be found on the plates at hand. 



Brief explanations may be given of the elements which are repre- 

 sented on plate 5. Figure 1 shows a bone of the cai'apace in which 

 the central area is large. The greatest diameter of the plate is 

 52.5 mm. ; that of the central area, 31 mm. At the upper border the 

 thickness is 29 mm.; on the lower 44 mm. The lower surface is 

 rough and uneven as if the plate had been attached by ligaments to 

 some other bone. The greatest diameter of the plate represented by 

 figure 2 is 53 mm. It will be seen that the central area is relatively 

 small. The thickness is 16 mm. The pla.te of figure 3 has as its 

 greatest diameter, at the outer surface, 50 mm. The central disk 

 comprises nearly the whole of the surface of the plate. The greatest 

 thickness is 22 mm. The diameter of the plate of figure 4 is 44 mm. ; 

 that of the central area, 17 mm. ; the thickness, 17 mm. The plate 

 shown by figure 5 has as the diameter of its sculptured surface 

 47 mm. ; the thickness is 17 mm. 



1 Amer. Nat., vol. 22, 1S8S, p. 345. = Idem, vol. 2S, p. 662, fig. 2. 



