272 
DR. A. GUNTHER ON GIGANTIC LAND-TORTOISES. 
horizontal, the fore part of the shell being strongly compressed, concave on each side, 
with the anterior margin strongly reverted — this part of the shell having an appearance 
which has been so aptly compared by Porter with a “ Spanish saddle.” The hind part 
of the shell is rounded, with a steep posterior profile, but more gently declivous on the 
sides, the marginal plates above the hind legs being arched outwards with the edge 
somewhat reverted, but less so than on the anterior marginal plates. The anterior as 
well as the posterior margins are irregularly scalloped. The plates are nearly smooth, 
the areolar portions passing gradually into the striated portions ; but the striae them- 
selves are inconspicuous, and in many places nearly obliterated. The sternum* is 
deeply concave, truncated in front and behind, the substance of the caudal plates and 
of the lateral portion of the abdominals being much thickened. 
I need not mention the scutellation of the head and legs, none of the Galapagos 
Tortoises showing any peculiarity in this respect. The tail is very short, and without 
terminal “ claw.” 
On comparing the carapace of the young example with that of equally small speci- 
mens of other species, we find the areolar spaces larger, the concentric strise deeply 
sculptured, but less numerous and further apart. Especially the sternal plates are 
smooth, with the striae partly obliterated. Posteriorly the sternum terminates in a 
notch (and this appears to be uniformly the case in very young specimens of all the 
species) ; but this notch is much shallower than in T. nigrita, obtuse-angular. 
The measurements of these two specimens are the following : — 
Length of carapace. Width of carapace. Depth of Sternum. Caudal plate. 
In str. line. Over eurv. In str. line. Over curv. carapace. Length. Width. Length. Width. 
Spec. inches. inches. inches. inches. inches. inches. inches. inches, inches. 
Adult . 33 40 23^ 40 17 24 21£ • 3£ 6 
Young .7 9f 5 8| 3| 4f 6f 1 1\ 
Skull . — The skull (Plates 37-39. fig. C) is comparatively smaller than that of T. 
elejpliantopus \ it is 4-f inches long, measured from the front margin of the intermaxillary 
to the occipital condyle, and 3f inches broad in its widest part between the zygomatic 
arches. The sutures between the various bones can be clearly traced ; and growth 
evidently had not ceased entirely, an observation confirmed by the examination of other 
bones extracted from the specimen. 1. The frontal region is flat, broad, passing into 
the very short snout, its greatest width (in front of the postfrontals) being about 
one half of the distance between the tympanic condyles. 2. The occipital crest is mode- 
rately developed, pointed behind, and rising but little above the level of the upper 
surface of the skull. 3. The tympanic case with the mastoid is produced backwards, 
the hind margin of the paroccipital forming a rather strong curve (Plate 37. fig. A, a). 
4. There is no hollow in front of the occipital condyle ; the space between the condyle 
* A large portion in tlie middle of the sternum has been cut out by the person who preserved the animal, 
in order to extract the contents of the shell. 
