AND PEUITONEAL CANALS IN CHELONIA.. 437 



vertebrates — an observation which was made by Townson three 

 quarters of a century ago, but which has been verified by other 

 naturalists and what I have myself noticed. Indeed the cloaca in 

 different species of Southern-Asiatic Emydes is not unfrequently 

 observed dilated with water, which they squirt out in considerable 

 jets when they retract their limbs and tail, as they generally do 

 when suddenly removed from that medium. Although I have ex- 

 amined, immediately after death, nearly one hundred individuals 

 belonging to those genera which are furnished with cloaca! blad- 

 ders, yet in no instance have the cloacal bladders been distended 

 with water ; whereas they have frequently yielded a yellowish 

 grumous substance, most especially abundant in those forms which 

 have these bladders provided with villi. It is also important to 

 note that they are in no way connected with any other viscus, 

 and that their only orifice is in the cloaca. On the other hand, 

 the azygos or partially divided bladder is generally more or less 

 filled, frequently to distention, in animals recently taken from the 

 water, with a clear limpid fluid not pure water. In the Crocodilia 

 the equivalents of these pouches are filled with a substance which 

 has the odour of musk ; but I have never particularly observed 

 that the Chelonia possessing these pouches are more characterized 

 by a peculiar odour than the pouchless forms. 



The function, however, which these bladders perform in the 

 economy of the semiterrestrial and semiaquatic Chelonia remains 

 yet to be determined by careful observation and experiment. 



One observation on the importance of their structures as an 

 indication of the habits of these animals, as illustrated by the genus 

 Pyxidea. The form Pyxidea moulwttii has been classed with the 

 Emydes ; but an examination of its cloaca reveals that, unlike those 

 animals, it is unprovided with cloacal bladders. And what are its 

 habits of life ? This is a question which I am enabled to answer 

 from the circumstance that I had two specimens under my obser- 

 vation over nine months, during which period they never entered 

 water, and did not exhibit any aquatic tendencies. 



All the Chelonia of South-eastern Asia which I have examined, 

 belonging to the genera Testudo, Geoemyda, Pangshura, Emys, 

 Batagur, Cmra, Cyclemys, Platysternum, Emyda, Trionyx, Chitra, 

 and Pelochelys, are distinguished by the presence of a pair of peri- 

 toneal canals which traverse the cloaca to the baycof the glaus of 

 the penis and clitoris. 



