THE LAND TORTOISES AND TERRAPINS 



2431 



The eyed terrapin (Morenia ocellata) from Burma, together with an 



e *" allied species from Bengal constitute a genus distinguished from the 



Terrapins preceding by the aperture of the posterior nostrils opening behind the 



line of the eyes. The typical species in which the shell measures 

 nearly nine inches in length, takes its name from the eye-like black spots 

 ringed with yellow which adorn each shield of the back portion of the carapace. 

 On the other hand, the Chinese terrapin (Ocadia sintnsis}, which is the sole exist- 

 ing representative of its genus, differs from Chrysemys in having the entoplastron 

 intersected by the groove formed by the junction between the pectoral and humeral 

 shields. The genus is of special interest as being represented by extinct species in 

 the upper Eocene strata of the south of England and the Continent. 



The remaining members of the family, which are arranged under 



four genera, and may be collectively known as batagurs, are exclu- 

 sively confined to India, Burma, and the Malayan region. They comprise the 

 largest fresh-water representatives of the 

 family, and are readily characterized by 

 the great development of the vertical bony 

 buttresses connecting the carapace with 

 the plastron, which project as walls within 

 the shell, so as partially to divide it into 

 compartments. Of the four genera, 

 Cachuga, which is represented by seven 

 species from India and Burma, is readily 

 recognized by the great elongation of the 

 fourth vertebral horny shield of the 

 carapace, which extends over four or five 

 of the underlying neural bones. The 

 smaller members, such as Smith's batagur 

 ( C. smithi} and the black - and - yellow 

 batagur (C. tectum}, of the Ganges and 

 Indus, are characterized by the fourth 

 vertebral shield terminating in front in a 

 narrow point. Whereas the former of 

 these has a depressed and feebly-keeled 

 shell, the latter, especially when young, 

 has the carapace much vaulted, and the 

 third vertebral shield produced behind 

 into a conical elevation forming the highest part of the shell. The name of black - 

 and -yellow batagur is derived from the irregular black patches on the bright yellow 

 plastron, the carapace being brown. I have taken specimens of this pretty little 

 batagur, which does not exceed eight inches in length and is generally much 

 smaller, near the fort at Calcutta. Like the under-mentioned dhongoka, it occurs 

 fossil in the Pliocene deposits of Northern India. The larger species of the genus, 

 such as the Indian dhongoka (C. dhongoka}, which grows to over fourteen inches, 

 has the fourth vertebral shield broad in front, instead of being narrowed to a point. 



UPPER SURFACE OF CARAPACE OF SMITH'S 



BATAGUR. 

 (Two-fifths natural size.) 



