482 ICHTHYOSAURIA chap. 



less flattened nodules towards tlie ends of the digits. These 

 carpal and phalangeal bones are common objects in amateurs' 

 collections ; they fit together l)y the short angular facets, while 

 the two flat and broader surfaces are those of the dorsal and 

 ventral sides. 



The Ichthyosaurs lived upon fishes and cuttlefish, as is indicated 

 by their dentition and the shape of the snout, and proved by 

 the coprolites, most of which are full of fragments of bones and 

 ganoid scales of fishes, and of the beaks and shells of cuttlefish ; 

 the larger of these true coprolites (literally " petrified dung)," in 

 coprolite-beds, contain also an abundance of other fossils, such as 

 Ammonites, Terebratulae, molluscs and fish-remains ; they are 

 several inches long, and many of them show on the outside ring-like 

 impressions, undoubtedly caused by a spiral valve of the intestinal 

 canal. In conformity with their absolutely aquatic life the 

 Ichthyosaurs were viviparous. Several well-preserved adult 

 specimens have been found, whicli contain the skeletons of one 

 or more rather large young within the body, in exactly the 

 position in which such foetal creatures would lie, namely, with 

 the head in the pelvic region of the mother, while the rest of the 

 body stretches along the vertebral column towards the chest. 

 The suggestion that these young Ichthyosaurs have been 

 swallowed by their cannibal elders is too idle to require serious 

 refutation. 



Until within a few years Ichthyosaurs were always restored 

 with a smooth and even back, but several well-preserved 

 specimens have come to light in Wlirtemberg which show the 

 complete contour of the animals, with a long, somewhat jagged 

 fin on the middle of the back. Since then not a few specimens 

 in various collections have on closer examination revealed the 

 same feature, except, of course, those in which the outlines of 

 the fin had been chiselled away in order to " improve " the look 

 of the slab. The fins were undoubtedly of the "adipose" kind; — 

 raised folds of tlie skin. The latter is now' known to have 

 been covered, at least at the bases of the dorsal fins, with hard 

 little scales, probably osteoderms. 



Many specimens are beautifully preserved, others present a 

 very peculiar appearance. They look, namely, like long rolls of 

 clay, and nobody but an expert would suspect an Ichthyosaurus 

 within such a log. The explanation is simple. The dead 



