7AL@ SIQILMIRS SHOU SI QUOIBIN TES: 
considerable development of the pubis, that parallels to some 
extent the extension of the coracoids. 
The oldest known remains of this genus come from the Rhae- 
tic beds of England and France (Autun). The most plentiful 
deposit is in the Lower Lias of Lyme-Regis in England; there 
are about twenty-six species known from these beds, a much 
larger number than is known from the continent. The continen- 
tal forms are found most commonly in the Lias beds in the 
vicinity of Holzmaden in Germany and near Banz and Autun in 
France. 
Eretmosaurus is quite similar to Pleszosaurus, being distin- — 
guished only by the greater development of the thoracic shield. 
A headless skeleton preserved in the British Museum is about 
nine feet long. 
Cimoltosaurus from the Cretaceous of the United States is 
characterized by the complete loss from the pectoral girdle of 
the clavicles and the interclavicle. The scapule and the cora- 
coids are extended until they meet the bone of the opposite side 
in the median line for a long distance and join each other in a 
broad suture. The whole arrangement is the most specialized of 
any in the group, both in the loss of the two elements and in the 
size of the coracoids and the scapula. Many similar forms that 
show the same thing, but with slightly different shaped bones, 
have been described as different genera, but were all united by 
Seeley in the genus Czmolosaurus of Leidy. These genera are 
Discosaurus, and Brimosaurus, from the same horizon of the Creta- 
ceous in Alabama and New Jersey as the original genus; Foly- 
cotylus from the Cretaceous of Kansas ( Niobrara) ; Elasmosaurus, 
from the same locality and horizon as the last, is of remark- 
able length, one specimen from near Fort Wallace in Kansas 
being 45 feet long, the neck alone being 22 feet and contain- 
ing 72 vertebre; Mawsaurus, from the Cretaceous of New Zea- 
land. 
A summary of some of the different forms referred to this 
genus will give some idea of the importance it attained in the 
latter part of the Mesozoic time. 
