98 Selections from Huxley 



most completely connected. The groups which are dying 

 out flourish, side by side, with the groups which are now 

 the dominant forms of life. 



Thus the chalk contains remains of those strange 

 5 flying and swimming reptiles, the pterodactyl, the ich- 

 thyosaurus, and the plesiosaurus, which are found in no 

 later deposits, but abounded in preceding ages. The 

 chambered shells called ammonites and belemnites, which 

 are so characteristic of the period preceding the cretaceous, 



10 in like manner die with it. 



But, amongst these fading remainders of a previous 

 state of things, are some very modern forms of life, 

 looking like Yankee peddlers among a tribe of Red In- 

 dians. Crocodiles of modern type appear; bony fishes, 



15 many of them very similar to existing species, almost 

 supplant the forms of fish which predominate in more 

 ancient seas; and many kinds of living shell-fish first 

 become known to us in the chalk. The vegetation ac- 

 quires a modern aspect. A few living animals are not even 



20 distinguishable as species from those which existed at that 

 remote epoch. The Globigerina of the present day, for 

 example, is not different specifically from that of the 

 chalk; and the same may be said of many other Fora- 

 minifera. I think it probable that critical and unpreju- 



25 diced examination will show that more than one species 

 of much higher animals have had a similar longevity; 

 but the only example which I can at present give con- 

 fidently is the snake's-head lamp-shell (Terebratulina 

 caput serpentis) , which lives in our English seas and 



30 abounded (as Terebratulina striata of authors) in the 

 chalk. 



The longest line of human ancestry must hide its dimin- 

 ished head before the pedigree of this insignificant shell- 

 fish. We Englishmen are proud to have an ancestor who 



