DR. A. GUNTHER ON GIGANTIC LAND-TORTOISES. 
265 
surface; in the middle of the vertebra the neural crest is split into two branches, 
diverging in the direction of the zygapophyses and leaving a deep triangular recess 
between them. The point of divergence forms a kind of summit ( a ) to this vertebra. 
The neural arch is deeply hollowed out (5) inwards of and behind each anterior zyga- 
pophysis to receive the zygapophysis of the preceding vertebra ; but no perforation of 
the bone takes place as in the extinct species of Rodriguez. The eighth vertebra, with 
its bipartite anterior and single posterior condyle, and with its expanded hamate poste- 
rior zygapophysis, does not differ from that of the Aldabra species. 
The measurements of the second to seventh cervical vertebrae are as follows : — 
2nd. 
3rd. 
4th. 
5th. 
6th. 
7th. 
millims. 
millims. 
millims. 
millims. 
millims. 
millims. 
Length of centrum 
. 55 
67 
85 
83 
85 
74 
Depth of centrum in the middle 
co 
28 
27 
27 
28 
53 
Horizontal width of middle of centrum 15 
17 
18 
20 
29 
27 
Width of anterior condyle 
. 15 
20 
19 
Width of anterior glenoid cavity 
30 
34 
40 
Width of posterior condyle . . . 
27 
32 
37 
Width of posterior glenoid cavity . 
. 19 
20 
43 
Distance of outer margins of anterior ' ] 
zygapophyses J 
j. 23 
CO 
35 
38 
40 
38 
Distance of outer margins of posterior , 
zygapophyses J 
J. 25 
26 
28 
30 
29 
46 
Of the dorsal vertebrae scarcely more than the measurements need to be noticed ; these 
are of some importance in comparison with the corresponding vertebrae in other species 
and also with the cervical vertebrae. The two heads of the first rib are slender, much 
divergent, leaving a wide triangular space between them and the first dorsal vertebra. 
The iliac bones abut against the pleurapophyses of the 9th, 10th, 11th, and 12th ver- 
tebrae, counting from the first dorsal vertebra. Their distal extremities unite to form 
the protuberance for the articulation of the ilium. 
Length of centrum of dorsal vertebrae : — 
1st. 2nd. 3rd. 4th. 5th. 6th. 7th. 8th. 9th. 10th. 11th. 12th. 
mm. mm. mm. mm. mm. mm. mm. mm. mm. mm. mm. mm. 
65 80 80 80 78 55 48 48 16 14 16 22 
The number of caudal vertebrae I have found to be the same in both our skeletons, 
viz. twenty- three. 
Iamb-bones . — In the scajgulary (Plate 44. figs. C, C') we notice the very 
obtuse angle at which the scapula and acromium meet. The body of the 
scapula proper is rather slender, compressed, trihedral in form, with its 
anterior side convex, as shown in the annexed figure, which represents a 
transverse section through its middle. The coracoid is not anchylosed 
to the scapula. The measurements of this bone are the following: — 
