TESTUDO PONDEEOSA. 37 
disappeared. For comparison with that species I give the length of the centra of the 
several dorsal vertebrse : — 
Dorsal vertebrsE 1st. 2nd. 3rd. 4th. 5th. 6th, 7th. 8th. 9th. 10th. 11th. 12th. 
Length o£ 
carapace, mm. mm. mm. mm. mm. mm. mm. mm. mm. mm. mm. mm, 
T. elephantina... 31 in. 45 70 82 86 80 65 48 39 24 19 16 16 
T. elephantina... 29^ in. 43 70 75 76 74 57 40 29 19 17 [lost] 
T.ponderosa ... 27^ in. 35 63 70 70 67 55 42 17 18 17 14 16 
The number of caudal vertebrce is twenty-five, as in T. elephantina, a close and sin- 
gular approximation to the numbers observed in the Galapagos Tortoises. Throughout 
this portion of the vertebral column the neural arch is much less thick and high than 
in T. elephantina. The first four vertebrse are much more depressed than in that 
species and have much longer diapophyses. The transition from the transversely 
elongate condyle of the fourth vertebra to the narrow and globular one of the fifth is 
abrupt. The sixth and seventh have their diapophyses obliquely directed forwards, 
whilst these processes are vertical to the axis of the vertebra from the eighth backwards, 
and gradually diminish in length. There is scarcely a trace of a hsemal ridge on 
the first nine vertebrae, the neural surface being longitudinally hollowed out. The last 
seven are ankylosed as in T. elephantina. The length of the entire caudal portion of 
the vertebral column is H\ inches (that of the carapace being 27|}; but the shortness 
of the tail is evidently due to sex. 
Limh-hones. — The scapulary (Plate XXIV. fig. A) is stout and massive. The angle 
at which the scapula proper and the acromion meet is very obtuse, about 130°. The 
body of the scapula is compressed, trihedral in form, a transverse section through its 
middle resembling exactly that of T. elephantopus (see p. 67) ; not only is the anterior 
surface convex, as in that species, but also one of the lateral surfaces is deeply scooped 
out. Acromion compressed, twisted round its longitudinal axis. The coracoid is 
ankylosed to the scapula, with the neck constricted and slightly twisted. The measure- 
ments of this bone, compared with those given of T. elephantina, are the following: — 
T. elephantina. T.ponderosa. 
Spec. c. 
Spec. 1. 
millim. 
millim. 
millim. 
Length of scapula (measured from the suture with the coracoid) . , 
. 265 
172 
160 
Circumference in its middle 
145 
73 
71 
90 
53 
42 
Length of coracoid 
150 
100 
84 
Greatest width of coracoid 
133 
80 
80 
Length of acromium 
110 
78 
84 
The humerus resembles so much that of T. elephantina that it will suffice to give the 
measurements : — 
