8 PROCEEDINGS OF THE NATIONAL MUSEUM vol.71 



In most species of the genus Terrapene both living and extinct, 

 the anterior end of the first vertebral is decidedly the widest. The 

 transverse sulci separating vertical scutes one and two, and two 

 and three, in specimen No. 25-144 A. C, differs from the other two 

 specimens in the strong interdigiting character of its course, as 

 plainly depicted in Figure 2. In the other specimens of this spe- 

 cies these sulci take a more or less straight course, or with only a 

 forward median loop. This median loop, which is only faintly 

 developed in No. 25-145 A. C, is conspicuously developed in No. 

 11,330 U.S.N.M. 



The posterior peripherals are strongly flared outward and slightly 

 upward. From the free border of the peripherals behind the hinge 

 line a decided sharp edged keel runs forward and joins the free 

 border of the anterior peripherals. The lateral peripherals imme- 

 diately in front of the anterior hinge attachment have their outer 

 borders strongly rolled up so as to form a shallow gutter, but for- 

 ward this roll gradually subsides, leaving the upper surface evenly 

 and shallowly concave. The nuchal scute is very much reduced 

 and on the upper surface of two of the specimens now before me 

 it barely reaches the free border of the shell. It has a length of 

 15.5 mm., and a width at the posterior end of 5 mm. 



The height of the supracaudals is 16 mm. in No. 25-144 A. C. 

 and 18 mm. in No. 11,330 U.S.N.M. and have a combined width of 

 48 and 50 mm., respectively. The hinder peripherals are strongly 

 flared outward relatively more than in T. major, which is living 

 in this region to-day. They are turned upward so that their lower 

 surfaces are horizontal. 



The lateral hinge articulation in No. 25-144 A. C. had a total 

 length of 87 mm., of which 62 mm. may be attributed to the pos- 

 terior lobe. Its thickness is 10 mm. 



Specimen No. 11,428 U.S.N.M. is unique in being the first mem- 

 ber of the present species found to have a complete plastron asso- 

 ciated with the carapace, and this association was of the greatest 

 importance in definitely deciding the status of T. antipeos, which 

 was based primarily upon a complete posterior lobe. In addition, 

 there are portions of four plastra, all from the Melbourne locality, 

 none of which could clearly be associated with carapacal parts. 

 These are No. 11,369 U.S.N.M., anterior plastral lobe; No. 11,370 

 U.S.N.M., greater part of a posterior lobe; No. 11,371 U.S.N.M., 

 anterior half of a posterior lobe; and No. 11,386 U.S.N.M., anterior 

 half of a posterior lobe. The description to follow is based upon 

 the plastron of specimen No. 11,428 U.S.N.M. Its greatest length 

 taken at the center is 242 mm. The anterior lobe is 93 mm. long 

 and 135 mm. wide on the hinge border; the posterior lobe is 150 

 mm. lon^ and 145 mm. wide. 



