THE NEW PLESIOSAUR 247 

AMERICAN PLESIOSAUR Elasmosaurus 
Restoration by Mr. Charles R. Knight. The long neck which was very likely 
much less flexible than here depicted, probably allowed this reptile to come up 
stealthily on prey from underneath while swimming near the bottom in shallow seas 
though a few more or less complete skeletons are preserved in this and other 
museums in America. 
Many skeletons, crushed and flattened but splendidly preserved, have 
been obtained from the cliffs of Lyme Regis and Whitby in England and 
from the great slate quarries of Holzmaden in Wiirttemberg, and are pre- 
served in various museums in Europe and America. The clay pits near 
Peterborough, England, have yielded a large series of Plesiosaur skeletons, 
most of which are in the British Museum. Fragmentary remains have 
also been described from India, South America, Australia and New Zealand. 
Some of the Plesiosaurs were of gigantic size, thirty to forty feet in 
length, but more commonly they were smaller, from six to fifteen feet. The 
length of neck and relative size of the head varied widely in different genera. 
The American Elasmosaurus was forty feet long with a small head and a 
neck twenty-two feet in length. The other extreme was Pliosaurus, equally 
huge in bulk but with the skull nearly five feet long and the neck only a 
foot and a half. The smaller Plesiosaurs were intermediate between these 
two extremes, but most of them had small heads. 
The restoration of Elasmosaurus, made by Mr. Charles R. Knight under 
the direction of the late Professor Cope, is based upon a nearly complete 
skeleton in the Cope collection now in the American Museum. Studies by 
