H. G0VIER SEELEY ON EMTS HORDWELLENSIS. 449 



Third pair of costal plates hammer-headed at their junction with 

 the neural plates, where they measure 1| inch in length; but 

 they become narrower, and where fractured measure only an inch in 

 length. 



The fourth costal plate where it joins the neural plate is 

 curved backward; it is about 1^ inch long, and gets narrower 

 from within outward. 



The fifth costal plate has the same form, and is an inch long. 



The Plastron. 



The plastron (fig. 2) is made up of the usual bones. A some- 

 what heart-shaped five-sided interclavicle (or sternum, fig. 2, i.c) is 

 enclosed in front by two clavicles (c), and behind by two hyosternal 

 bones (%), which are followed by two hyposternal elements (hp). 

 The plastron is more than usually convex from front to back. 



Fig. 2. — Plastron o/Emys hordwellensis. (One third natural size.) 



c. Clavicle, i.c. Interclavicle. hy. Hyosternal. hp. Hyposternal. 



The gular scutes are small, and become narrower from the median 

 line outward ; each measures 1| inch from the median line trans- 

 versely, and J inch from before backward. The postgular or humeral 

 scutes are large, and have the posterior margin convex, though, the 



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