MONOGEAPH 
ON THE 
FOSSIL REPTILIA OP THE LONDON CLAY. 
YOL. II. 
RESTORATION OF CHELONE GIGAS, Ow., A SPECIES INDICATED BY A 
FRAGMENT OF THE FEMUR IN A FORMER MONOGRAPH.^ 
In the ' Monograpli on the Fossil ReptiHa of the London Clay, Supplement to the 
Order Chelonia,'^ the proximal end of the femur of a very large marine Chelonian is 
noticed and figured in PI. XXIX, fig. 5, and the size of the species in proportion to the 
largest known existing Turtle, an individual of Chelone mydas, which weighed 150 lbs., 
is illustrated by a subjoined figure of the entire femur of that individual (fig. 5'). The 
breadth of the proximal end of this femur across the trochanters is barely two inches, the 
same dimension of the fossil is four inches ten lines. 
In 1858 the British Museum obtained the upper portion of the cranium of a Chelone 
from the same formation and locality (Sheppey), corresponding in magnitude with the 
above-cited portion of fossil femur, and it was registered and labelled as of the Chelone 
gigas?' 
In the present year, 1879, W. H. Shrubsole, Esq., F.G.S., submitted to ray exami- 
nation an almost entire cranium and other portions of the skeleton of the same gigantic 
species of Turtle, which had been exhumed from the septarian modification of the London 
Clay at Sheppey. The following are dimensions of the fossil (PI. I) and of the largest 
cranium of Chelone mydas in the Zoological Department of the British Museum. 
1 Palseontographical Society's Volume, issued for the year 1849, 4to., PI. XXIX, fig. 5, 1850. 
3 ' Palseontology,' 8vo., 2nd ed., 1861, p. 317. 
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