4 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.68 



tions of sutures. On each side of this tract, at right angles with it, 

 is another surface which probably was connected with the ilium. Its 

 surface resembles that of a suture. The two other fragments of the 

 carapace also bekmged above the sacrum. Away from the median 

 line the caiajiace varies in thickness from 23 mm. to 27 mm. The 

 dermal s(^-utes vary in diameter from 36 nun. to 46 mm. (pi. 1, fig. 1). 

 In general, they are not coossified and the borders of the fragments 

 follow the sutures. Each scute is ornamented by a rosettelike figure. 

 The central portion of each rosette is much larger tlian the periph- 

 eral parts. The groove around the central area and those radiating" 

 from it are wide and deep. On a casual view the rosettes resemble 

 much those shown in Lydekker's work.'^ Close inspection shows dif- 

 ferences. In Lydekker's figure the peripheral pieces of each rosette 

 are separated from those of the surrounding rosettes by a very dis- 

 tinct groove. If in the Sinton specimen the groove which appears 

 to surround the rosette is followed one comes into contact with the 

 central area of other rosettes. In fact, the grooves Avhich separate 

 contiguous rosettes and wdiich usually follow the bone sutures are 

 nearly suppressed in the Sinton specimen. Occasionally traces of 

 them may be found, as shown in the illustration (pi. 1, fig. 1). 



In another res]:)ect the rosettes differ from those cited from Lydek- 

 ker's work. In that specimen the central areas are somewhat exca- 

 vated, but the peripheral areas are flat. In the Sinton glyptodon 

 both the central and the peripheral areas are hollowed out. Each 

 excavation of the peripherals occupies adjoining areas of two 

 rosettes. 



On comparing the carapace here described with that of the Wolfe 

 City specimen it is seen that in the latter the central areas are 

 often relatively smaller, sometimes hardly larger than the periph- 

 erals; also that all the areas are either flat or convex. Often, too, 

 in the groove surrounding the central areas there may be found 

 three or four large pores; in the Sinton animal none, one, or two. 

 In the Wolfe City glyptodon it is observed that occasionally rosettes 

 are found some of w^hose peripheral areas are not separated by 

 grooves from those of adjoining areas. 



The writer has not seen the femur which was obtained on Aransas 

 River, but Doctor Francis sent a carefully drawn sketch of the 

 natural size. When this is compared with the femur of the Wolfe 

 City specimen no differences are observed. It is possible that the 

 differences existing between the Wolfe City specimen and that 

 found near Sinton are indicative of distinct species. Considering, 

 however, the variability of the elements of the skull and of the 

 skeleton, the w^riter believes it better to refer the specimen to Cope's 

 Glyptodon petaliferus. 



"An. Mus. La Plata, Palaeout. Argentina, vol. 3, 1894, pi. 3, flg. 2. 



