October] 

 1956 J 



Baker, The Swall 'ownifj of Stones fay Animals 



83 



However, the finding of heaps of stones in the pelvic region of the skeleton 

 resolved the douhts that reptiles of that period did swallow stones. 



Further evidence was ohtained by the rock types of these polished pebbles, 

 as they did not always compare with those of the surrounding country, and 

 frequently they were the only pebbles in the deposits in which the bones 

 were found. 



H. (i. Seeley, in 1877. describes the finding, at the base of the Gault. in 

 Folkestone, Fngland ( Upper Cretaceous), "about a peck of ovate and 

 rounded pebbles, chiefly of opaque milky quartz, some of black metamorphosed 

 slate, and a few of fine-grained sandstone and hornstone ; some of the pebbles 

 showing a veined character, such as might be derived from the neighbouring 

 Palaeozoic rocks of the north of France". 



Fig. 1 — Protoplotus bcauforti, from the Tertiary of West Sumatra, with a 

 compact mass of pebbles associated with bone remains. 



In his "Descriptive Catalogue of the Marine Reptiles of the Oxford Clay", 

 C. W. Andrews (1910) states that "in a skeleton of Peloneustes (a Cre- 

 taceous Plesiosaur) was obtained a hard mass, lying within the ribs, contain- 

 ing many stones of various sizes from that of a hen's egg downwards, and 

 no doubt representing the fossilized contents of the stomach. The stones of 

 various kimls. included quartz, sandstone and gneiss, and for the most part 

 were rather angular with the edges somewhat rounded off". 



In the south central plains of North America, numerous sauropodian 

 skeletons have been unearthed, and with these have been associated highly 

 polished pebbles. 



Barnum Brown ( 1904 ) states that "in nearly every instance a large 

 number of siliceous stones were found associated with the bones of Plesiosaurs. 



