352 



BAUR. 



[Vol. IV. 



tudinata in fresh specimens. In Chelys, Hydraspis, and espe- 

 cially in Emydura,^ the epigastroid is enormously developed, 

 more than in any other form. As it is well known, the ectopubes 

 and the branch connecting the entoischia with the ectoischia, 

 are co-ossified with the plastron, the ilium with the carapace. 

 In all the Pleurodira examined the epigastroid is united to the 

 plastron by ligament : this ligament is attached on the posterior 

 part of the suture between the hypoplastra. The epigastroid in 

 Chelodina^ is only about half as long as in the other Chelyiidae. 

 In the Podocnemididge and Sternothseridae it is well developed, 

 but not so elongated as in the Chelyiidae. 



Fig, io. — Chelys fimbriata, Schn. 

 Pelvis from above. 



E, Epigastroid. 

 M, Mesogastroid. 

 H, Hypogastroid. 



In young animals the gastroid cartilage is complete, but in very 

 old animals entopubes are united, and also the entoischia. The 

 hypogastroid is very small, or quite reduced ; but the mesogas- 

 troid is always cartilaginous, forming a long element, separating 

 entopubes and entoischia. In none of the Pleurodira the ento- 

 pubes touch the entoischia. In all living Pleurodira, as far as I 



^ This fact was first seen by Hoffmann, who figured the long epigastroid in 

 Chely?nys victoriac, in his Reptilien, PI. VII, Fig. 6. 



2 I may mention here the peculiar fact, that in all the specimens of Chelodina 

 examined by me there was only a single frontal, without any trace of a middle suture. 

 This is the only exception among Tortoises, so far as I know. 



