‘Parr IID, Sucr. ii. §1.] JURASSIC. Gg 
which the ordinary reptilian characters were united to others, par- 
ticularly in the hinder part of the skeleton, like those of birds. 
Among the Jurassic deinosaurs the most important European genera 
are Compsognathus, Megalosaurus (Fig. 379), and Ceteosaurus. In 
Compsognathus, from the Solenhoten Limestone, the bird-like affinities 
are strikingly exhibited, as it possessed a long neck, small head, and 
long hind limbs on which it must have hopped or walked. The 
Megalosaurus of the Stonesfield Slate 1s estimated to have had a 
length of 25 feet, and to have weighed two or three tons. It fre- 
quented the shores of the lagoons, walking probably on its massive 
hind legs, and feeding on the molluscs, fishes, and perhaps the small 
mammals of the district. Still more gigantic was the Ceteosaurus, 

Fic. 374.—Jurassico GASTEROPODS. 
a, Natica hulliana (Lyc.) (Lower Oolite) ; b, Nerita costulata (Desh.) (Lower Oolite, 
nat. size and mag.) ; c, Natica globosa (Roem.) (Upper Oolite). 
which, according to Phillips, probably reached when standing a 
height of not less than 10 feet and a length of 50 feet. It seems to 
have been a marsh-loving or river-side animal, living on the ferns, 
cycads, and conifers among which it dwelt. But these monsters of 
the Old World were surpassed in dimensions by some discovered in 
recent years by Professor Marsh in the Jurassic beds of Colorado. 
In particular the Atlantosaurus was built on so huge a scale that its 
femur alone is more than 8 feet high. The corresponding bone of 
the most gigantic elephant looks like that of a dwarf when put 
beside this fossil. The whole length of the animal is supposed to have 
been not much short of 100 feet, with a height of 30 feet or more. 
Contemporaneous with these huge creatures, however, there existed 
in Jurassic time in North America diminutive forms haying such 
