XO. 12 



SMITHSONIAN EXPLORATIONS, I917 



9 



the round white spots), six Ijruad ril)s, and a lar.^e taih liranchiae 

 or .^ills shine throu,i;h the thin shell as well as traces of the legs. 

 Another curious form, figure 5, is a soft-bodied holothurian with 

 many flexible podia or false legs. A small, round shell ha])])encd to 

 rest on the sea bottom just where the head part of the animal was 

 later pressed down upon it. Another soft-bodied form is Portalia 

 lulra (figs. 6 and 7). which is related to the sea cucttmber or Holo- 

 thurian which nia\- be seen growing on the sea bed at Catalina Island. 

 California. The shale bed at the quarry suggests that the waters 

 of the acient Cambrian sea above it swarmed with life just as the 

 ocean does to-dav at Catalina Island. But this was long before the 



Fig. 10. — Graiiny, tlie mountain stiuirrd. Frcqiu-nlly sliowcrs of l)ri>ki.-n 

 rock and dirt were thrown hy the blasting all ahout t!ie place where Granny 

 was sitting, hut she invariably dodged under iirotecting slalis and appeared 

 soon after as unconcerned as tliough nothing had hapjiened. I'liotooraph liy 

 W'alcott, 1917. 



advent of fislies on the earth so there were no fish, and no traces 

 of them occur in the fossil bc(l. Tlie ^n])crl) ])rcscr\ ation of the 

 fossils at the quarry is all the more reniarkabli' when we consider 

 that they have ])Cen buried for t\\eiil\- million ycar> or more .uid 

 subject to all the vicissituilo llial rork matcrirds experience fnmi ihe 

 time that they are siin]il\- hardened mud bnrie(l bi'iieath tliousands 

 of feet in thickness of la\er^ of mu<l. sand, and pebbles. Tlun all 

 were changed b\' pressure and chemicali/alion into solid beiN ni 

 sandstone, slatv shale, and limi'slone. These were lati'r compressed 

 and elevated into mounlain ranges and more or less wdrn a\\a\- by 



