444 FOSSIL TURTLES OF NORTH AMERICA. 



procoracoid process is 125 mm. The two branches of the bone make an angle of about 120 

 with each other. The bone is a stout one, the width across it at the glenoid fossa being 50 mm. 



The left humerus (figs. 594, 595) is complete, with the exception of a missing part of the 

 ulnar process. It is a stout bone, but not so much curved as in some species of the genus, even 

 less so than in Gopherus polyphemus. The total length is 200 mm.; the diameter thru the 

 head and ulnar process is too mm.; thru the external and internal condyles, 76 mm.; and thru 

 the narrowest portion of the shaft, 35 mm. The planes of the ulnar and radial tuberosities 

 make a small angle between them, about the same as in G. polyphemus. The trochlear surface 

 is well defined. When the bone is in its natural position, this surface is directed strongly down- 

 ward. It is traverst from the dorsal to the ventral surface by a broad and rather deep groove. 



The left radius and ulna are represented in fig. 596, but more or less hidden by portions 

 of the dermal armor. They are stout bones, the ulna having a length of no mm., a breadth 

 across the middle of the shaft of 29 mm., across the distal end of 43 mm. The radius has 

 a total length of 112 mm. The head is expanded. The slender portion of the shaft has a 

 diameter ol 16 mm. 



The bones of the digits are all present, except the ungual phalanx of the first. Some of the 

 bones are slightly disturbed and their positions are somewhat obscured by the dermal bones; 

 but some notes are obtained regarding them. The radiale is a small bone which does not ex- 

 clude the first carpal from extensive connection with the radius. This radiale has a rhombic 

 superior surface, articulates by its proximal surface with the intermedium, and by its radial 

 surface with the radius. The intermedium is elongated in the direction of the axis of the limb, 

 articulates by its proximal end with the ulna and by its radial surface with the upper portion 

 ofthearticulatory surface of the radius. The length of the intermedium is 24mm. The ulnare 

 is not sufficiently enlarged to exclude the fifth carpal from contact with the ulna. 



Carpale i is rather larger than the radiale, and articulates extensively with the distal end 

 of the radius. The ungual phalanges vary in length from 34 mm. in the first to 38 mm. in the 

 last. They are flat or slightly convex both above and below, and their distal ends are blunt. 



In the small size of the radiale and ulnare the bones of this carpus resemble most those 

 of Gopherus polyphemus, but in the latter carpale 2 also joins the radius. 



Of the pelvis there are present portions of both sides. The ilium has a total length of 

 155 mm. Its greatest diameter, at the upper border of the acetabulum, is 71 mm. The lateral 

 process of each pubic bone is broad and flat, and the distal end is rounded. 



Both femora have been preserved. They too are stout bones, little bent, and having the 

 distal articular surface directed strongly downward, when the bone is in its natural position. 

 That of the right side is shown in figs. 597, 598. The total length, measured parallel with the 

 axis of the bone, is 150 mm. Thru the head and the trochanter the distance is 77 mm.; thru 

 the tuberosities, 63 mm. The shortest diameter of the shaft is 24 mm. A ridge separates 

 the fibular condyle from that for the tibia. The latter has a broad groove running dorso- 

 ventrally. 



The tibia (fig. 598) is also a relatively short and thick bone, the length being 99 mm., the 

 distance thru the tuberosities 46 mm. 



Most of the bones of the left hind foot (fig. 599) are so completely hidden by the dermal 

 armor that, with the exception of the ungual phalanges and calcaneum, they can not be 

 studied. The calcaneum resembles that of other species of Testudo. The ungual phalanges, 

 4 in number, resemble those of the forefoot. 



Fig. 600 represents the terminal six vertebrae of the tail. The lateral processes are some- 

 what elongated, so that the end of the tail is paddle-shaped, instead of pointed. The last three 

 vertebrae are consolidated into one mass. Two or three vertebra; above those shown in fig. 60 1 

 have their lateral processes standing at right angles with the centra. 



Professor Cope made the observation that this species possest numerous osseous bosses on 

 the limbs, doubtless ossifications of large marginal and other dermal scutes. These are said to 

 have a low apex, central or concentric. Further description was not furnisht. More complete 

 preparation of his specimens, especially No. 1325, shows that these bosses were found on the 

 fore limbs, the hind limbs, and on the tail and the region surrounding the latter. Fig. 595 

 shows a number of these osseous scutes on the upper surface of the distal end of the humerus. 

 They are rather small and closely joined. No doubt, they lay embedded in the skin that cov- 



