4680 THE ZooLoGiIst—NOVEMBER, 1875. 
of the elbow, by the double alveolar ridge of their jaws. Among 
the carapaces which I have examined I can distinguish five forms ; 
of the first four severally, two are more nearly related to each other 
than to the other pair, the fifth being intermediate between these 
two pairs. . The degree of distinctness and affinity which obtains 
in the carapaces is expressed clearly and in exactly the same 
manner in the skulls, as will be seen from the following charac- 
teristics :— 
1. In the first species (Testudo elephantopus of Harlan) the 
shell is broad and depressed, with the upper anterior profile sub- 
horizontal in the male, and with corrugated but not deeply 
sculptured plates. Sternum truncated behind. The snout is very 
short. Skull with an immensely developed and raised occipital 
crest, with a sharp outer pterygoid edge, and a deep recess in front 
of the occipital condyle. The skeleton of a fully adult male 
example and one of an immature female are in the Oxford 
Museum and the collection of the Royal College of Surgeons. 
Young individuals are by no means scarce in collections. Either 
this species or the next appears to have inhabited James’ Island. 
2. Testudo nigrita has likewise a broad shell, which, however, is 
considerably higher than in the former species; the anterior profile 
in the male is declivous, and the plates are deeply sculptured. 
Sternum with a triangular excision behind. The snout is longer, 
and the occipital crest low; but the outer pterygoid edge is equally 
sharp, and the recess in front of the occipital condyle equally deep 
as in T. elephantopus. The principal specimens examined by 
myself of this species, are one 41 inches long, in the British 
Museum—the type of the specimen (described and named by 
Dumeril and Borbron) in the collection of the Royal College of 
Surgeons; and the large skull in the British Museum, figured by 
Dr. Gray under the name of Testudo planiceps. 
8. Porter’s account of the race inhabiting Charles Island is 
sufficiently characteristic to enable us to recognize it in an adult 
specimen, the shell of which is elongate, compressed into the form 
of a Spanish saddle, and of a dull colour without any polish. The 
sternum is truncated behind. Skull with the outer pterygoid edge 
flattened, with the tympanic cavity much produced backwards, 
and without recess in front of the occipital condyle. The only 
adult example which I have examined is 33 inches long, and 
belongs to the Museum of Science and Arts, Edinburgh. It was 
