SAUROPTERYGIA 209 



numerous pointed teeth, indicative of a predatory and carni- 

 vorous nature in all the species ; but these differed from one 

 another in regard to the relative strength of the jaws, and the 

 relative size and length of the teeth. 



Masses of masticated bones and scales of extinct fishes, 

 that lived in the same seas and at the same period as the 

 Ichthyosaurus, have been found under the ribs of fossil speci- 

 mens, in the situation where the stomach of the animal was 

 placed ; smaller, harder, and more digested masses, containing 

 also fish-bones and scales, have been found, bearing the impres- 

 sion of the structure of the internal surface of the intestine of 

 the great predatory sea-lizard. One of these " coprolites " is 

 figured beneath the skeleton in fig. 68. 



In tracing the evidences of creative power from the earlier 

 to the later formations of the earth's crust, remains of the 

 Ichthyosaurus are first found in the lower lias, and occur more 

 or less abundantly through all the superincumbent secondary 

 strata up to, and inclusive of, the chalk formations. They are 

 most numerous in the lias and oolite, and the largest and most 

 characteristic species have been found in these formations. 



More than thirty species of Ichthyosaurus are known to 

 the writer, many of which have been described or defined. 



Order 4. — Sauropterygia.* 



No post-orbital and supra-temporal bones : large temporal 

 and other vacuities between certain cranial bones ; a 

 foramen parietale ; two antorbital nostrils ; teeth simple, 

 in distinct sockets of premaxillary, maxillary, and pre- 

 mandibular bones, rarely on the palatine or pterygoid 

 bones ; maxillaries larger than premaxillaries. Limbs 

 natatory ; not more than five digits. A sacrum of one 

 or two vertebrae for the attachment of the pelvic arch 

 in some, numerous cervical vertebrae in most. Pleura- 



* ~Zavpo s, a lizard ; n-Wpuf , a fin. 

 P 



