ART. 15 



PLEISTOCENE FOSSIL TURTLES — GILMORE 



The anterior lobe as in most of the box turtles is convex from 

 back to front on the ventral surface. The lateral posterior borders 

 are slightly constricted behind the pectoral-humeral sulcus, but more 

 forward rapidly round inward to the broad but slightly convex 

 anterior border of the lip. The hinge border is slightly sinuous 

 with a pronounced groove across its posterior median surface. At 

 the center of the hinge the bone has a thickness of only 7 mm. but 

 thickens to 10 mm. toward either side. Specimen No. 11369 

 U.S.N.M., a smaller individual, has 

 a thickness of 13.5 mm. at the mid- 

 dle, exceeding the type of T. antipex. 

 On the upper side above the gular 

 area the lobe is broadly excavated 

 and the lip portion is shallowly 

 concave transversely, which has a 

 greatest width of about 59 mm. 

 The horn-covered upper surface is 

 16 mm. wide. The forms of the 

 scutes are shown in Figure 4. The 

 triangular gular scutes have a great- 

 est length on the midline of 44 mm. ; 

 the humerals 25 mm., and pectorals 

 22 mm. The borders of the ento- 

 plastron can not be made out in this 

 specimen. In a detached lobe at- 

 tributed to this species. Hay ^ de- 

 scribes it as being circular with a 

 diameter of 44 mm. The posterior 

 two-thirds of thef ree border is acute. 



The posterior lobe, as in the type 

 of T. antipex^ has all of the bones 

 consolidated into one piece (see 

 Plate 5). The course of the hypo- 

 xiphiplastral suture is scarcely dis- 

 tinguishable. The under surface of 

 this lobe is -deeply and broadly concave, thus indicating the male 

 sex of the individual. At the midline in front, the bone has a 

 thickness of 8 mm., but becomes thicker posteriorly. The lateral 

 hinge lines are 47 mm. long. The horn-covered surfaces posterior 

 to the lateral hinges are 20 mm. wide. The free edges are acute. 

 There is a slight constriction at the femoral-anal sulcus, but other- 

 wise the lobe presents an evenly rounded border that is slightly 

 notched on the midline. Measured at the center the xiphiplastron 

 has a length of 85 mm., the hypoplastron 65 mm. The median 



Fig. 4. — Plastbon of Tekrapene- can- 

 ALICCLATA Hat. No. 11,428 U.S.N.M. 



AB, abdominal SCDTEi ; AN, ANAL 

 SCUTE ; FEM, FEMORAL SCUTE ; G, 

 GULAR scute; HUMj HUMERAL SCUTE; 

 PEC, PECTORAL SCUTE. OnB-THIRD 

 NATURAL SIZE 



s Eighth Ann. Kept. State Geol. Survey of Florida, 1916, p. 59. 



