REMARKABLE TORTOISE, TESTUDO LOVERIBGII. 485 



with me in my three principal amendments to his original 

 description : — 



1. That the type-specimens are fully adult. 



2. That the adults have bony neural and costal plates present 

 to a certain degree. 



3. That the young has a more or less depressed carapace. 



Characteristics. 



Testuclo loveridgii is already well known as the Soft-shelled 

 Tortoise with the flat carapace, both these characteristics being 

 entirely foreign to Testuclo as previously defined. 



In general appearance it looks as if it had been crushed in youth 

 and had only survived by a miracle. When taken in the hand 

 alive it has a boneless feeling which is uncanny ; both carapace 

 and plastron react to pressure on the abdominal region with a 

 springy motion, and the animal is able to inflate itsblf to a slight 

 degree. 



Mr. Boulenger pointed out in his note that in the case of the 

 plastron this softness is due to an enormous diamond-shaped 

 fenestra, usually met with in the newly-hatched or very young 

 of other species. The viscera thus exposed are protected by 

 extremely thick, soft, dermis of a very tough nature. 



The ti'ue structure of the carapace was revealed by X-rays quite 

 accidentally, my original object being to compare the supposedly 

 boneless adult with the young, in which the ribs show normal 

 development. When viewed through the fluorescent screen, the 

 adults presented an extraordinary appearance, the ribless vertebrae 

 and more or less normal limb-girdles being overlaid b}^ a bony 

 network, intimately correlated with the net of sutures between 

 the epidermal shields, and formed by the partial development of 

 the neural and costal plates which had been apparently wanting, 

 and which in other species compose the solid bony carapace (vide 

 Pis. II. & III.). The significance of this bony netwoi'k only 

 became clear after considerable study of the X-ray plate taken 

 at the time. The skeleton subsequently prepared corroborated 

 every detail revealed in this plate, and also showed that the 

 vertebrse are very remarkable in form. The animal is further 

 rexxiarkable in possessing what appear to be teeth, acrodont in 

 type and similar to those met with in Agamoid lizards. Their 

 regularity renders them quite unlike the seiTations met with in 

 some tortoises. The horny sheaths of the alveolar ridges are 

 similar Iv denticulated. 



In the detailed description which follows, these structures will 

 be dealt with at greater length. 



The species is still in a state of great instability, for apart from 

 the immense range of variation to which it is subject, many 

 abnormalities occur, such as the presence of horny shields projDer 

 to the more primitive Chelonians. 



34* 



