42 



CHELONTA. 



49465. The imperfect skull ; from the London Clay (Lower Eocene) 

 {Fig.) of the Isle of Sheppy. The type; figured by Konig in 

 his ' Icones Foss. Sectiles,' pi. xviii. rig. 232. The borders 

 of the orbits are broken away, and the occipital, nasal, 

 and premaxillary regions are also imperfect. On the 

 palate, so far as can be seen, the characters of the pteryg- 

 oids and the contour of the apertures of the temporal f ossae 

 are of the general type of those of A.cuneiceps. The external 

 surface of the cranial bones is rugose, but this appears to 

 be due to erosion. The boundaries of an occipital shield 

 dividing the paroccipitals and joining the interparietal 

 are distinctly visible. The characters of the mandible are 

 well shown. In the nearly similar specimen in the 

 Museum of the Eoyal College of Surgeons, figured in 

 Owen's ' History of British Fossil Eeptilia,' Chelonia, 

 pi. xvii. a., and also in pi. i. of his ' Eeptilia of the 

 London Clay,' as the type of Ghelone breviceps, no occipital 

 shield is shown; and its absence is made a specific 

 character. In the restored palate figured in pi. xvii. of 

 the former work, it would appear from the present 

 specimen that the anterior expansion of the pterygoids is 

 insufiiciently given ; and the ectopterygoicl processes are 

 not distinct enough. No history. 



28854. The imperfect skull of a smaller individual ; from Sheppey. 

 The cranial bones have the same rugose character as in 

 the last. The outline of the short and broad interparietal 

 and frontal shields is shown, and there are traces of the 

 occipital shield. Purchased, 1854. 



32386. The imperfect skull of an individual somewhat smaller than 

 the type ; from Sheppey. In this specimen the surface 

 of the cranial bones has not been eroded. The borders of 

 the orbits and nares are broken; but the mandible is 

 nearly entire. The occipital shield, if present, must have 

 been pushed back to the supraoccipital spine, and the 

 paroccipital shields unite in the middle line ; while the 

 interparietal is long and narrow with a re-entering 

 posterior angle. Purchased. About 1857. 



38955. A smaller skull ; from Sheppey. Figured in the accom- 



(Fig.) panying woodcut. This specimen is imperfect posteriorly, 



but shows the contour of the greater part of the cranium 



