XVI. THE INDIAN MUD-TURTLES 
(TRIONYCHIDAB). 
By N. ANNANDALE, D.Sc., F'.A.S.B., Superintendent, 
Indian Museum. 
(Plates V—VI.) 
The main object of the present paper is to supplement 
Mr. G. A. Boulenger’s admirable account of the Indian Chelonia pub- 
lished in the volume on Reptilia and Batrachia in the ‘‘ Fauna of 
British India.’’ It is now twelve years since this volume appeared 
and although additions to our knowledge of the Trionychidae since 
that date have not been very numerous or important so far as 
India is concerned, the fact that its author had not access to the 
bulk of the large collection accumulated in the Indian Museum by 
the late Dr. J. Anderson and his contemporaries and successors 
rendered certain omissions unavoidable. 
I have been able, moreover, to institute special inquiries 
into the distribution of certain species and races and have received 
assistance in so doing from several naturalists in different parts of 
India, especially from Dr. J. R. Henderson, Superintendent of the 
Madras Museum, and from my colleague Mr. B. L,. Chaudhuri, 
who has supplied me with valuable information. 
One species and two subspecies not recognized by Mr. 
Boulenger in the “‘ Fauna’’ are here described. The species 
belongs to the genus Zvonyx and is interesting because it repre- 
sents this genus in a geographical area in which information about 
its distribution was peculiarly scanty. 
This Tvionyx was described, it must be confessed inade- 
quately, by Dr. Anderson, who named it T. wigricans. It 
inhabits a tract of country intermediate between the Brahmaputra 
river-system and the Arrakan streams in which a Burmo-Malay 
species of the genus first makes its appearance. I have found it 
necessary, moreover, to recognize the races of Emyda that occur 
in Chota Nagpur and Orissa on the one hand and in Ceylon on 
the other as distinct subspecies. The name intermedia is here 
proposed for the former race, while Gray’s ‘“‘ ceylonensis’’ is 
available for the latter. 
LIST OF THE INDIAN TRIONYCHIDAE. 
I. Dogania subplana (Geoffr.). Mergui, Malay Peninsula, Suma- 
tra, Sinkep I., Java, Borneo, 
and the Philippines. 
