336 MOSTLY MAMMALS 
specially engaged in carrying tortoises from Rodriguez to 
Mauritius took six thousand at once. Such a drain could 
not but tell rapidly on the supply, and by the early part 
of: the last century the Mascarenes were denuded of their 
tortoise-fauna. 
The Malagasy tortoise (Testudo gvandidier’) appears, as 
already said, to have been exterminated before Europeans 
had any knowledge of the islands, but beautifully pre- 
served shells (wanting the horny shields) have been dis- 
covered, three of which are exhibited in the Natural 
History Museum. Among the Mascarene tortoises, most 
of which are distinguished from those of Aldabra_ by their 
long thick necks and the absence of a nuchal shield* to 
the shell, five or six species are known in a sub-fossil 
state from Mauritius. To one of these (Z. zxdica) special 
interest attaches from the circumstance that till about 1871 
all the tortoises from the islands of the Indian Ocean were 
referred to by that name. Of equal interest, although 
from a totally different point of view, is the Rodriguez 
tortoise (7. vosmaert), on account of the extreme tenuity 
of its bony shell—a feature shared by certain of the 
Galapagos species, and indicative that the thick shell 
characteristic of tortoises generally is not required by the 
island forms which have no enemies. 
A tortoise received in company with two others from the 
Seychelles in 1894 by Mr. Rothschild, and now living at 
Tring, is believed to be one of the Mascarene species, with 
which it agrees in the characters referred to above. It 
may have come from one of the smaller islands, and thus 
be different from any of the named forms, although it 
is difficult to determine this during its life. Very little 
* The nuchal shield is the single symmetrical horny plate found 
in the middle line of the front margin of the shell of most tortoises, 
