198 THE JURA'SSIC EPOCH. 



Fig. 308. Restoration of the saurians of the jura'ssic epoch. 



appeared. The numerous terebra'tulae, which lived in this epoch 

 oeionged to species entirely different from those seen in the pre 

 ceding seas ; but there was found a great number of mollusks with 

 chambered shells, in general called ammonites, the race of which, 

 as yet little developed, had begun to appear in the seas of the trias ; 

 there existed bele'mnites, the remains of which, until then unknown, 

 are numerous from the lias to the chalk : and the gry'phea arcua'ta 

 multiplied there for a moment, to disappear afterwards, when the 

 lias was formed, and to give place to other species of the same 

 genus. 



As at present, coral reefs were formed in those seas, remains of 

 which are found, showing a mean temperature, analogous to that 

 of our intertropic seas. 



On the land, fresh-wnter lakes without doubt supported palu'di- 

 nse, and fresh-water strea.ns carried helices, remains of which are 

 now found in the Portland group. 



There must have existed also, on land, several species of insects, 

 which served to feed the pteroda'ctyls, the remains of which seem 

 o show they were coleoptera and neuroptera, resembling the bu- 

 prestes and libe'llulse. Small marsupial mammals, analogous to 

 opossums, were met there, a skeleton of which was found in the 

 beds of Stonesfield. But these creatures seem to have been in 

 small numbers, if we judge from the few remains that have been 

 us yet found, and no one of the great animals which characterize 

 *be parisian epoch has been found with them. 



