JURASSIC PERIOD 
And this small creature would forsooth appear 
The most advanced of all the fishes here. 
In Nature's fateful story, oft indeed 
The smallest forms are those that take the lead. 50 
Though all its ancient genera are gone, 
"Sea-urchin " life is gamely pressing on. 
Molluskan life, with all its ups and downs, 
Expands exuberant in congenial zones. 
New forms of water-snail crawl on their way, 55 
With likeness more to those that live to-day. 
True oysters now are spreading far and wide, 
And forming banks beneath the flowing tide. 
Big members too there are, as if their food 
Abundant were, and climate all they would. 60 
Along the coast new Ammonoids are spreading, 
The older, Trias, forms fast superseding : 
But though the race adaptive powers has shown, 
And strives in altered forms to hold its own ; 
Yet not in numbers does it seem to grow, 65 
And palmy days it not again will know. 
The once great " Lamp-shells " still are on the wane ; 
Nor do the Nautiloids in force remain : 
And all such forms as in their ranks of yore 
Were seen in long straight shells are now no more : 70 
And but one family can the race display, 
Yet one whose line will live on till to-day. 
61 
