ISO INTESTINAL STRUCTURE OF ICHTHYOSAURUS. 
ages that contain the remains of carnivorous rep- 
tiles, and have been recognized in many and dis- 
tant regions both of Europe and America.* 
The certainty of the origin of these Coprolites 
is established, by their frequent presence in the 
abdominal region of fossil skeletons of Ichthyo- 
sauri found in the lias of Lyme Regis. One of 
the most remarkable of these is represented in 
PL 13; the coprolitic matter loaded with fish 
scales, within the ribs of these and similar spe- 
cimens, is identical in appearance and chemical 
composition with the insulated coprolites that 
occur in the same strata with the skeletons. f 
* Professor Jaeger has recently discovered many Coprolites 
in the alum slate of Gaildorf in Wirtemberg; a formation 
which he considers to be in. the lower region of that part of the 
new red sandstone formation which in Germany is called Keuper ; 
and which contains the remains of two species of Saurians. 
In the United States Dr. Dekay has also discovered Copro- 
lites in the Green-sand formation of Monmouth, in New Jersey, 
see PI. 15, Fig. 13. 
f This specimen has been presented by Viscount Cole to the 
Geolodcal Collection of the University of Oxford. It affords 
decisive proof that the substances in question cannot be referred 
to adventitious matter, placed accidentally in contact with the 
fossil body, inasmuch as the large coprolitic mass is enclosed 
between the back bone and the right and left series of the ribs, of 
which the greater number remain nearly in their natural position. 
The quantity of this coprolite is prodigious, when compared with 
the size of the animal in which it occurs; and if we were not 
acquainted with the powers of the digestive organs of reptiles and 
fishes, and their capacity of gorging the larger animals that form 
their prey ; the great space within these fossil skeletons of Ich- 
thyosauri, which is occasionally filled with coprolitic matter, 
would appear inexplicable. 
